mirror of
https://github.com/moodle/moodle.git
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2134 lines
83 KiB
PHP
2134 lines
83 KiB
PHP
<?php
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// This file is part of Moodle - http://moodle.org/
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//
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// Moodle is free software: you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// Moodle is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
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/**
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* Abstract database driver class.
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*
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* @package core
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* @subpackage dml
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* @copyright 2008 Petr Skoda (http://skodak.org)
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* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
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*/
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defined('MOODLE_INTERNAL') || die();
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require_once($CFG->libdir.'/dml/database_column_info.php');
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require_once($CFG->libdir.'/dml/moodle_recordset.php');
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require_once($CFG->libdir.'/dml/moodle_transaction.php');
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/// GLOBAL CONSTANTS /////////////////////////////////////////////////////////
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/** Bitmask, indicates :name type parameters are supported by db backend. */
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define('SQL_PARAMS_NAMED', 1);
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/** Bitmask, indicates ? type parameters are supported by db backend. */
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define('SQL_PARAMS_QM', 2);
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/** Bitmask, indicates $1, $2, ... type parameters are supported by db backend. */
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define('SQL_PARAMS_DOLLAR', 4);
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/** Normal select query, reading only */
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define('SQL_QUERY_SELECT', 1);
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/** Insert select query, writing */
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define('SQL_QUERY_INSERT', 2);
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/** Update select query, writing */
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define('SQL_QUERY_UPDATE', 3);
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/** Query changing db structure, writing */
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define('SQL_QUERY_STRUCTURE', 4);
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/** Auxiliary query done by driver, setting connection config, getting table info, etc. */
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define('SQL_QUERY_AUX', 5);
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/**
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* Abstract class representing moodle database interface.
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*/
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abstract class moodle_database {
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/** @var database_manager db manager which allows db structure modifications */
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protected $database_manager;
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/** @var moodle_temptables temptables manager to provide cross-db support for temp tables */
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protected $temptables;
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/** @var array cache of column info */
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protected $columns = array(); // I wish we had a shared memory cache for this :-(
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/** @var array cache of table info */
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protected $tables = null;
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// db connection options
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/** @var string db host name */
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protected $dbhost;
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/** @var string db host user */
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protected $dbuser;
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/** @var string db host password */
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protected $dbpass;
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/** @var string db name */
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protected $dbname;
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/** @var string table prefix */
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protected $prefix;
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/** @var array Database or driver specific options, such as sockets or TCPIP db connections */
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protected $dboptions;
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/** @var bool true means non-moodle external database used.*/
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protected $external;
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/** @var int The database reads (performance counter).*/
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protected $reads = 0;
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/** @var int The database writes (performance counter).*/
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protected $writes = 0;
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/** @var int Debug level */
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protected $debug = 0;
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/** @var string last query sql */
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protected $last_sql;
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/** @var array last query parameters */
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protected $last_params;
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/** @var int last query type */
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protected $last_type;
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/** @var string last extra info */
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protected $last_extrainfo;
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/** @var float last time in seconds with milisecond precision */
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protected $last_time;
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/** @var bool flag indicating logging of query in progress, prevents infinite loops */
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private $loggingquery = false;
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/** @var bool true if db used for db sessions */
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protected $used_for_db_sessions = false;
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/** @var array open transactions */
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private $transactions = array();
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/** @var bool force rollback of all current transactions */
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private $force_rollback = false;
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/** @var int internal temporary variable */
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private $fix_sql_params_i;
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/**
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* Constructor - instantiates the database, specifying if it's external (connect to other systems) or no (Moodle DB)
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* note this has effect to decide if prefix checks must be performed or no
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* @param bool true means external database used
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*/
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public function __construct($external=false) {
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$this->external = $external;
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}
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/**
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* Destructor - cleans up and flushes everything needed.
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*/
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public function __destruct() {
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$this->dispose();
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}
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/**
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* Detects if all needed PHP stuff installed.
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* Note: can be used before connect()
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* @return mixed true if ok, string if something
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*/
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public abstract function driver_installed();
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/**
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* Returns database table prefix
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* Note: can be used before connect()
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* @return string database table prefix
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*/
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public function get_prefix() {
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return $this->prefix;
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}
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/**
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* Loads and returns a database instance with the specified type and library.
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* @param string $type database type of the driver (mysql, postgres7, mssql, etc)
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* @param string $library database library of the driver (adodb, pdo, native, etc)
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* @return moodle_database driver object or null if error
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*/
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public static function get_driver_instance($type, $library) {
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global $CFG;
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$classname = $type.'_'.$library.'_moodle_database';
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$libfile = "$CFG->libdir/dml/$classname.php";
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if (!file_exists($libfile)) {
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return null;
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}
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require_once($libfile);
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return new $classname();
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}
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/**
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* Returns database family type - describes SQL dialect
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* Note: can be used before connect()
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* @return string db family name (mysql, postgres, mssql, oracle, etc.)
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*/
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public abstract function get_dbfamily();
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/**
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* Returns more specific database driver type
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* Note: can be used before connect()
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* @return string db type mysql, mysqli, postgres7
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*/
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protected abstract function get_dbtype();
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/**
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* Returns general database library name
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* Note: can be used before connect()
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* @return string db type pdo, native
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*/
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protected abstract function get_dblibrary();
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/**
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* Returns localised database type name
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* Note: can be used before connect()
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* @return string
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*/
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public abstract function get_name();
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/**
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* Returns localised database configuration help.
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* Note: can be used before connect()
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* @return string
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*/
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public abstract function get_configuration_help();
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/**
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* Returns localised database description
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* Note: can be used before connect()
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* @return string
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*/
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public abstract function get_configuration_hints();
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/**
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* Returns db related part of config.php
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* @return object
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*/
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public function export_dbconfig() {
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$cfg = new stdClass();
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$cfg->dbtype = $this->get_dbtype();
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$cfg->dblibrary = $this->get_dblibrary();
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$cfg->dbhost = $this->dbhost;
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$cfg->dbname = $this->dbname;
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$cfg->dbuser = $this->dbuser;
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$cfg->dbpass = $this->dbpass;
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$cfg->prefix = $this->prefix;
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if ($this->dboptions) {
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$cfg->dboptions = $this->dboptions;
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}
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return $cfg;
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}
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/**
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* Connect to db
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* Must be called before other methods.
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* @param string $dbhost
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* @param string $dbuser
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* @param string $dbpass
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* @param string $dbname
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* @param mixed $prefix string means moodle db prefix, false used for external databases where prefix not used
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* @param array $dboptions driver specific options
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* @return bool true
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* @throws dml_connection_exception if error
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*/
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public abstract function connect($dbhost, $dbuser, $dbpass, $dbname, $prefix, array $dboptions=null);
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/**
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* Store various database settings
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* @param string $dbhost
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* @param string $dbuser
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* @param string $dbpass
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* @param string $dbname
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* @param mixed $prefix string means moodle db prefix, false used for external databases where prefix not used
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* @param array $dboptions driver specific options
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* @return void
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*/
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protected function store_settings($dbhost, $dbuser, $dbpass, $dbname, $prefix, array $dboptions=null) {
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$this->dbhost = $dbhost;
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$this->dbuser = $dbuser;
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$this->dbpass = $dbpass;
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$this->dbname = $dbname;
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$this->prefix = $prefix;
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$this->dboptions = (array)$dboptions;
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}
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/**
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* Attempt to create the database
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* @param string $dbhost
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* @param string $dbuser
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* @param string $dbpass
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* @param string $dbname
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*
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* @return bool success
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*/
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public function create_database($dbhost, $dbuser, $dbpass, $dbname, array $dboptions=null) {
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return false;
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}
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/**
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* Close database connection and release all resources
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* and memory (especially circular memory references).
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* Do NOT use connect() again, create a new instance if needed.
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*/
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public function dispose() {
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if ($this->transactions) {
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// this should not happen, it usually indicates wrong catching of exceptions,
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// because all transactions should be finished manually or in default exception handler.
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// unfortunately we can not access global $CFG any more and can not print debug,
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// the diagnostic info should be printed in footer instead
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$lowesttransaction = end($this->transactions);
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$backtrace = $lowesttransaction->get_backtrace();
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error_log('Potential coding error - active database transaction detected when disposing database:'."\n".format_backtrace($backtrace, true));
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$this->force_transaction_rollback();
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}
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if ($this->used_for_db_sessions) {
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// this is needed because we need to save session to db before closing it
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session_get_instance()->write_close();
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$this->used_for_db_sessions = false;
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}
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if ($this->temptables) {
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$this->temptables->dispose();
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$this->temptables = null;
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}
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if ($this->database_manager) {
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$this->database_manager->dispose();
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$this->database_manager = null;
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}
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$this->columns = array();
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$this->tables = null;
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}
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/**
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* Called before each db query.
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* @param string $sql
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* @param array array of parameters
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* @param int $type type of query
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* @param mixed $extrainfo driver specific extra information
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* @return void
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*/
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protected function query_start($sql, array $params=null, $type, $extrainfo=null) {
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if ($this->loggingquery) {
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return;
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}
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$this->last_sql = $sql;
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$this->last_params = $params;
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$this->last_type = $type;
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$this->last_extrainfo = $extrainfo;
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$this->last_time = microtime(true);
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switch ($type) {
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case SQL_QUERY_SELECT:
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case SQL_QUERY_AUX:
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$this->reads++;
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break;
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case SQL_QUERY_INSERT:
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case SQL_QUERY_UPDATE:
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case SQL_QUERY_STRUCTURE:
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$this->writes++;
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}
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$this->print_debug($sql, $params);
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}
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/**
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* Called immediately after each db query.
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* @param mixed db specific result
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* @return void
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*/
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protected function query_end($result) {
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if ($this->loggingquery) {
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return;
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}
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if ($result !== false) {
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$this->query_log();
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// free memory
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$this->last_sql = null;
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$this->last_params = null;
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return;
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}
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// remember current info, log queries may alter it
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$type = $this->last_type;
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$sql = $this->last_sql;
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$params = $this->last_params;
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$time = microtime(true) - $this->last_time;
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$error = $this->get_last_error();
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$this->query_log($error);
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switch ($type) {
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case SQL_QUERY_SELECT:
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case SQL_QUERY_AUX:
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throw new dml_read_exception($error, $sql, $params);
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case SQL_QUERY_INSERT:
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case SQL_QUERY_UPDATE:
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throw new dml_write_exception($error, $sql, $params);
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case SQL_QUERY_STRUCTURE:
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$this->get_manager(); // includes ddl exceptions classes ;-)
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throw new ddl_change_structure_exception($error, $sql);
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}
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}
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/**
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* Log last database query if requested
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* @param mixed string error or false if not error
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* @return void
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*/
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public function query_log($error=false) {
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$logall = !empty($this->dboptions['logall']);
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$logslow = !empty($this->dboptions['logslow']) ? $this->dboptions['logslow'] : false;
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$logerrors = !empty($this->dboptions['logerrors']);
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$iserror = ($error !== false);
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$time = microtime(true) - $this->last_time;
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if ($logall or ($logslow and ($logslow < ($time+0.00001))) or ($iserror and $logerrors)) {
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$this->loggingquery = true;
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try {
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$backtrace = debug_backtrace();
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if ($backtrace) {
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//remove query_log()
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array_shift($backtrace);
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}
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if ($backtrace) {
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//remove query_end()
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array_shift($backtrace);
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}
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$log = new object();
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$log->qtype = $this->last_type;
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$log->sqltext = $this->last_sql;
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$log->sqlparams = var_export((array)$this->last_params, true);
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$log->error = (int)$iserror;
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$log->info = $iserror ? $error : null;
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$log->backtrace = format_backtrace($backtrace, true);
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$log->exectime = $time;
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$log->timelogged = time();
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$this->insert_record('log_queries', $log);
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} catch (Exception $ignored) {
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}
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$this->loggingquery = false;
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}
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}
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/**
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* Returns database server info array
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* @return array
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*/
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public abstract function get_server_info();
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/**
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* Returns supported query parameter types
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* @return bitmask
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*/
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protected abstract function allowed_param_types();
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/**
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* Returns last error reported by database engine.
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*/
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public abstract function get_last_error();
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/**
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* Print sql debug info
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* @param string $sql query which caused problems
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* @param array $params optional query parameters
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* @param mixed $obj optional library specific object
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*/
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protected function print_debug($sql, array $params=null, $obj=null) {
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if (!$this->get_debug()) {
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return;
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}
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if (CLI_SCRIPT) {
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echo "--------------------------------\n";
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echo $sql."\n";
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if (!is_null($params)) {
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echo "[".var_export($params, true)."]\n";
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}
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echo "--------------------------------\n";
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} else {
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echo "<hr />\n";
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echo s($sql)."\n";
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if (!is_null($params)) {
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echo "[".s(var_export($params, true))."]\n";
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}
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echo "<hr />\n";
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}
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}
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/**
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* Returns SQL WHERE conditions.
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*
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* @param array conditions - must not contain numeric indexes
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* @return array sql part and params
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*/
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protected function where_clause(array $conditions=null) {
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$allowed_types = $this->allowed_param_types();
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if (empty($conditions)) {
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return array('', array());
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}
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$where = array();
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$params = array();
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foreach ($conditions as $key=>$value) {
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if (is_int($key)) {
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throw new dml_exception('invalidnumkey');
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}
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if (is_null($value)) {
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$where[] = "$key IS NULL";
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} else {
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if ($allowed_types & SQL_PARAMS_NAMED) {
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$normkey = trim(preg_replace('/[^a-zA-Z0-9-_]/', '_', $key), '-_'); // Need to normalize key names
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$where[] = "$key = :$normkey"; // because they can contain, originally,
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$params[$normkey] = $value; // spaces and other forbidden chars when
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} else { // using sql_xxx() functions and friends.
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$where[] = "$key = ?";
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$params[] = $value;
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}
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}
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}
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$where = implode(" AND ", $where);
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return array($where, $params);
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}
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/**
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* Returns SQL WHERE conditions for the ..._list methods.
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*
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* @param string $field the name of a field.
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* @param array $values the values field might take.
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* @return array sql part and params
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*/
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protected function where_clause_list($field, array $values) {
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$params = array();
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$select = array();
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$values = (array)$values;
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foreach ($values as $value) {
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if (is_bool($value)) {
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$value = (int)$value;
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}
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if (is_null($value)) {
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$select[] = "$field IS NULL";
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} else {
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$select[] = "$field = ?";
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$params[] = $value;
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}
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}
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$select = implode(" OR ", $select);
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return array($select, $params);
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}
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/**
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* Constructs IN() or = sql fragment
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* @param mixed $items single or array of values
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* @param int $type bound param type SQL_PARAMS_QM or SQL_PARAMS_NAMED
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* @param string named param placeholder start
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* @param bool true means equal, false not equal
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* @return array - $sql and $params
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*/
|
|
public function get_in_or_equal($items, $type=SQL_PARAMS_QM, $start='param0000', $equal=true) {
|
|
if (is_array($items) and empty($items)) {
|
|
throw new coding_exception('moodle_database::get_in_or_equal() does not accept empty arrays');
|
|
}
|
|
if ($type == SQL_PARAMS_QM) {
|
|
if (!is_array($items) or count($items) == 1) {
|
|
$sql = $equal ? '= ?' : '<> ?';
|
|
$items = (array)$items;
|
|
$params = array_values($items);
|
|
} else {
|
|
if ($equal) {
|
|
$sql = 'IN ('.implode(',', array_fill(0, count($items), '?')).')';
|
|
} else {
|
|
$sql = 'NOT IN ('.implode(',', array_fill(0, count($items), '?')).')';
|
|
}
|
|
$params = array_values($items);
|
|
}
|
|
|
|
} else if ($type == SQL_PARAMS_NAMED) {
|
|
if (!is_array($items)){
|
|
$sql = $equal ? "= :$start" : "<> :$start";
|
|
$params = array($start=>$items);
|
|
} else if (count($items) == 1) {
|
|
$sql = $equal ? "= :$start" : "<> :$start";
|
|
$item = reset($items);
|
|
$params = array($start=>$item);
|
|
} else {
|
|
$params = array();
|
|
$sql = array();
|
|
foreach ($items as $item) {
|
|
$params[$start] = $item;
|
|
$sql[] = ':'.$start++;
|
|
}
|
|
if ($equal) {
|
|
$sql = 'IN ('.implode(',', $sql).')';
|
|
} else {
|
|
$sql = 'NOT IN ('.implode(',', $sql).')';
|
|
}
|
|
}
|
|
|
|
} else {
|
|
throw new dml_exception('typenotimplement');
|
|
}
|
|
return array($sql, $params);
|
|
}
|
|
|
|
/**
|
|
* Converts short table name {tablename} to real table name
|
|
* @param string sql
|
|
* @return string sql
|
|
*/
|
|
protected function fix_table_names($sql) {
|
|
return preg_replace('/\{([a-z][a-z0-9_]*)\}/', $this->prefix.'$1', $sql);
|
|
}
|
|
|
|
/** Internal function */
|
|
private function _fix_sql_params_dollar_callback($match) {
|
|
$this->fix_sql_params_i++;
|
|
return "\$".$this->fix_sql_params_i;
|
|
}
|
|
|
|
/**
|
|
* Normalizes sql query parameters and verifies parameters.
|
|
* @param string $sql query or part of it
|
|
* @param array $params query parameters
|
|
*/
|
|
public function fix_sql_params($sql, array $params=null) {
|
|
$params = (array)$params; // mke null array if needed
|
|
$allowed_types = $this->allowed_param_types();
|
|
|
|
// convert table names
|
|
$sql = $this->fix_table_names($sql);
|
|
|
|
// NICOLAS C: Fixed regexp for negative backwards lookahead of double colons. Thanks for Sam Marshall's help
|
|
$named_count = preg_match_all('/(?<!:):[a-z][a-z0-9_]*/', $sql, $named_matches); // :: used in pgsql casts
|
|
$dollar_count = preg_match_all('/\$[1-9][0-9]*/', $sql, $dollar_matches);
|
|
$q_count = substr_count($sql, '?');
|
|
|
|
$count = 0;
|
|
|
|
if ($named_count) {
|
|
$type = SQL_PARAMS_NAMED;
|
|
$count = $named_count;
|
|
|
|
}
|
|
if ($dollar_count) {
|
|
if ($count) {
|
|
throw new dml_exception('mixedtypesqlparam');
|
|
}
|
|
$type = SQL_PARAMS_DOLLAR;
|
|
$count = $dollar_count;
|
|
|
|
}
|
|
if ($q_count) {
|
|
if ($count) {
|
|
throw new dml_exception('mixedtypesqlparam');
|
|
}
|
|
$type = SQL_PARAMS_QM;
|
|
$count = $q_count;
|
|
|
|
}
|
|
|
|
if (!$count) {
|
|
// ignore params
|
|
if ($allowed_types & SQL_PARAMS_NAMED) {
|
|
return array($sql, array(), SQL_PARAMS_NAMED);
|
|
} else if ($allowed_types & SQL_PARAMS_QM) {
|
|
return array($sql, array(), SQL_PARAMS_QM);
|
|
} else {
|
|
return array($sql, array(), SQL_PARAMS_DOLLAR);
|
|
}
|
|
}
|
|
|
|
if ($count > count($params)) {
|
|
$a = new stdClass;
|
|
$a->expected = $count;
|
|
$a->actual = count($params);
|
|
throw new dml_exception('invalidqueryparam', $a);
|
|
}
|
|
|
|
$target_type = $allowed_types;
|
|
|
|
if ($type & $allowed_types) { // bitwise AND
|
|
if ($count == count($params)) {
|
|
if ($type == SQL_PARAMS_QM) {
|
|
return array($sql, array_values($params), SQL_PARAMS_QM); // 0-based array required
|
|
} else {
|
|
//better do the validation of names below
|
|
}
|
|
}
|
|
// needs some fixing or validation - there might be more params than needed
|
|
$target_type = $type;
|
|
}
|
|
|
|
if ($type == SQL_PARAMS_NAMED) {
|
|
$finalparams = array();
|
|
foreach ($named_matches[0] as $key) {
|
|
$key = trim($key, ':');
|
|
if (!array_key_exists($key, $params)) {
|
|
throw new dml_exception('missingkeyinsql', $key, '');
|
|
}
|
|
$finalparams[$key] = $params[$key];
|
|
}
|
|
if ($count != count($finalparams)) {
|
|
throw new dml_exception('duplicateparaminsql');
|
|
}
|
|
|
|
if ($target_type & SQL_PARAMS_QM) {
|
|
$sql = preg_replace('/(?<!:):[a-z][a-z0-9_]*/', '?', $sql);
|
|
return array($sql, array_values($finalparams), SQL_PARAMS_QM); // 0-based required
|
|
} else if ($target_type & SQL_PARAMS_NAMED) {
|
|
return array($sql, $finalparams, SQL_PARAMS_NAMED);
|
|
} else { // $type & SQL_PARAMS_DOLLAR
|
|
//lambda-style functions eat memory - we use globals instead :-(
|
|
$this->fix_sql_params_i = 0;
|
|
$sql = preg_replace_callback('/(?<!:):[a-z][a-z0-9_]*/', array($this, '_fix_sql_params_dollar_callback'), $sql);
|
|
return array($sql, array_values($finalparams), SQL_PARAMS_DOLLAR); // 0-based required
|
|
}
|
|
|
|
} else if ($type == SQL_PARAMS_DOLLAR) {
|
|
if ($target_type & SQL_PARAMS_DOLLAR) {
|
|
return array($sql, array_values($params), SQL_PARAMS_DOLLAR); // 0-based required
|
|
} else if ($target_type & SQL_PARAMS_QM) {
|
|
$sql = preg_replace('/\$[0-9]+/', '?', $sql);
|
|
return array($sql, array_values($params), SQL_PARAMS_QM); // 0-based required
|
|
} else { //$target_type & SQL_PARAMS_NAMED
|
|
$sql = preg_replace('/\$([0-9]+)/', ':param\\1', $sql);
|
|
$finalparams = array();
|
|
foreach ($params as $key=>$param) {
|
|
$key++;
|
|
$finalparams['param'.$key] = $param;
|
|
}
|
|
return array($sql, $finalparams, SQL_PARAMS_NAMED);
|
|
}
|
|
|
|
} else { // $type == SQL_PARAMS_QM
|
|
if (count($params) != $count) {
|
|
$params = array_slice($params, 0, $count);
|
|
}
|
|
|
|
if ($target_type & SQL_PARAMS_QM) {
|
|
return array($sql, array_values($params), SQL_PARAMS_QM); // 0-based required
|
|
} else if ($target_type & SQL_PARAMS_NAMED) {
|
|
$finalparams = array();
|
|
$pname = 'param0';
|
|
$parts = explode('?', $sql);
|
|
$sql = array_shift($parts);
|
|
foreach ($parts as $part) {
|
|
$param = array_shift($params);
|
|
$pname++;
|
|
$sql .= ':'.$pname.$part;
|
|
$finalparams[$pname] = $param;
|
|
}
|
|
return array($sql, $finalparams, SQL_PARAMS_NAMED);
|
|
} else { // $type & SQL_PARAMS_DOLLAR
|
|
//lambda-style functions eat memory - we use globals instead :-(
|
|
$this->fix_sql_params_i = 0;
|
|
$sql = preg_replace_callback('/\?/', array($this, '_fix_sql_params_dollar_callback'), $sql);
|
|
return array($sql, array_values($params), SQL_PARAMS_DOLLAR); // 0-based required
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Return tables in database WITHOUT current prefix
|
|
* @return array of table names in lowercase and without prefix
|
|
*/
|
|
public abstract function get_tables($usecache=true);
|
|
|
|
/**
|
|
* Return table indexes - everything lowercased
|
|
* @return array of arrays
|
|
*/
|
|
public abstract function get_indexes($table);
|
|
|
|
/**
|
|
* Returns datailed information about columns in table. This information is cached internally.
|
|
* @param string $table name
|
|
* @param bool $usecache
|
|
* @return array array of database_column_info objects indexed with column names
|
|
*/
|
|
public abstract function get_columns($table, $usecache=true);
|
|
|
|
/**
|
|
* Normalise values based in RDBMS dependencies (booleans, LOBs...)
|
|
*
|
|
* @param database_column_info $column column metadata corresponding with the value we are going to normalise
|
|
* @param mixed $value value we are going to normalise
|
|
* @return mixed the normalised value
|
|
*/
|
|
protected abstract function normalise_value($column, $value);
|
|
|
|
/**
|
|
* Reset internal column details cache
|
|
* @param string $table - empty means all, or one if name of table given
|
|
* @return void
|
|
*/
|
|
public function reset_caches() {
|
|
$this->columns = array();
|
|
$this->tables = null;
|
|
}
|
|
|
|
/**
|
|
* Returns sql generator used for db manipulation.
|
|
* Used mostly in upgrade.php scripts.
|
|
* @return object database_manager instance
|
|
*/
|
|
public function get_manager() {
|
|
global $CFG;
|
|
|
|
if (!$this->database_manager) {
|
|
require_once($CFG->libdir.'/ddllib.php');
|
|
|
|
$classname = $this->get_dbfamily().'_sql_generator';
|
|
require_once("$CFG->libdir/ddl/$classname.php");
|
|
$generator = new $classname($this, $this->temptables);
|
|
|
|
$this->database_manager = new database_manager($this, $generator);
|
|
}
|
|
return $this->database_manager;
|
|
}
|
|
|
|
/**
|
|
* Attempt to change db encoding toUTF-8 if possible
|
|
* @return bool success
|
|
*/
|
|
public function change_db_encoding() {
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* Is db in unicode mode?
|
|
* @return bool
|
|
*/
|
|
public function setup_is_unicodedb() {
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* Enable/disable very detailed debugging
|
|
* @param bool $state
|
|
*/
|
|
public function set_debug($state) {
|
|
$this->debug = $state;
|
|
}
|
|
|
|
/**
|
|
* Returns debug status
|
|
* @return bool $state
|
|
*/
|
|
public function get_debug() {
|
|
return $this->debug;
|
|
}
|
|
|
|
/**
|
|
* Enable/disable detailed sql logging
|
|
* @param bool $state
|
|
*/
|
|
public function set_logging($state) {
|
|
// adodb sql logging shares one table without prefix per db - this is no longer acceptable :-(
|
|
// we must create one table shared by all drivers
|
|
}
|
|
|
|
/**
|
|
* Do NOT use in code, to be used by database_manager only!
|
|
* @param string $sql query
|
|
* @return bool true
|
|
* @throws dml_exception if error
|
|
*/
|
|
public abstract function change_database_structure($sql);
|
|
|
|
/**
|
|
* Execute general sql query. Should be used only when no other method suitable.
|
|
* Do NOT use this to make changes in db structure, use database_manager::execute_sql() instead!
|
|
* @param string $sql query
|
|
* @param array $params query parameters
|
|
* @return bool true
|
|
* @throws dml_exception if error
|
|
*/
|
|
public abstract function execute($sql, array $params=null);
|
|
|
|
/**
|
|
* Get a number of records as a moodle_recordset where all the given conditions met.
|
|
*
|
|
* Selects records from the table $table.
|
|
*
|
|
* If specified, only records meeting $conditions.
|
|
*
|
|
* If specified, the results will be sorted as specified by $sort. This
|
|
* is added to the SQL as "ORDER BY $sort". Example values of $sort
|
|
* might be "time ASC" or "time DESC".
|
|
*
|
|
* If $fields is specified, only those fields are returned.
|
|
*
|
|
* Since this method is a little less readable, use of it should be restricted to
|
|
* code where it's possible there might be large datasets being returned. For known
|
|
* small datasets use get_records - it leads to simpler code.
|
|
*
|
|
* If you only want some of the records, specify $limitfrom and $limitnum.
|
|
* The query will skip the first $limitfrom records (according to the sort
|
|
* order) and then return the next $limitnum records. If either of $limitfrom
|
|
* or $limitnum is specified, both must be present.
|
|
*
|
|
* The return value is a moodle_recordset
|
|
* if the query succeeds. If an error occurs, false is returned.
|
|
*
|
|
* @param string $table the table to query.
|
|
* @param array $conditions optional array $fieldname=>requestedvalue with AND in between
|
|
* @param string $sort an order to sort the results in (optional, a valid SQL ORDER BY parameter).
|
|
* @param string $fields a comma separated list of fields to return (optional, by default all fields are returned).
|
|
* @param int $limitfrom return a subset of records, starting at this point (optional, required if $limitnum is set).
|
|
* @param int $limitnum return a subset comprising this many records (optional, required if $limitfrom is set).
|
|
* @return object moodle_recordset instance
|
|
* @throws dml_exception if error
|
|
*/
|
|
public function get_recordset($table, array $conditions=null, $sort='', $fields='*', $limitfrom=0, $limitnum=0) {
|
|
list($select, $params) = $this->where_clause($conditions);
|
|
return $this->get_recordset_select($table, $select, $params, $sort, $fields, $limitfrom, $limitnum);
|
|
}
|
|
|
|
/**
|
|
* Get a number of records as a moodle_recordset where one field match one list of values.
|
|
*
|
|
* Only records where $field takes one of the values $values are returned.
|
|
* $values must be an array of values.
|
|
*
|
|
* Other arguments and the return type as for @see function get_recordset.
|
|
*
|
|
* @param string $table the table to query.
|
|
* @param string $field a field to check (optional).
|
|
* @param array $values array of values the field must have
|
|
* @param string $sort an order to sort the results in (optional, a valid SQL ORDER BY parameter).
|
|
* @param string $fields a comma separated list of fields to return (optional, by default all fields are returned).
|
|
* @param int $limitfrom return a subset of records, starting at this point (optional, required if $limitnum is set).
|
|
* @param int $limitnum return a subset comprising this many records (optional, required if $limitfrom is set).
|
|
* @return object moodle_recordset instance
|
|
* @throws dml_exception if error
|
|
*/
|
|
public function get_recordset_list($table, $field, array $values, $sort='', $fields='*', $limitfrom=0, $limitnum=0) {
|
|
list($select, $params) = $this->where_clause_list($field, $values);
|
|
if (empty($select)) {
|
|
$select = '? = ?'; /// Fake condition, won't return rows ever. MDL-17645
|
|
$params = array(1, 2);
|
|
}
|
|
return $this->get_recordset_select($table, $select, $params, $sort, $fields, $limitfrom, $limitnum);
|
|
}
|
|
|
|
/**
|
|
* Get a number of records as a moodle_recordset which match a particular WHERE clause.
|
|
*
|
|
* If given, $select is used as the SELECT parameter in the SQL query,
|
|
* otherwise all records from the table are returned.
|
|
*
|
|
* Other arguments and the return type as for @see function get_recordset.
|
|
*
|
|
* @param string $table the table to query.
|
|
* @param string $select A fragment of SQL to be used in a where clause in the SQL call.
|
|
* @param array $params array of sql parameters
|
|
* @param string $sort an order to sort the results in (optional, a valid SQL ORDER BY parameter).
|
|
* @param string $fields a comma separated list of fields to return (optional, by default all fields are returned).
|
|
* @param int $limitfrom return a subset of records, starting at this point (optional, required if $limitnum is set).
|
|
* @param int $limitnum return a subset comprising this many records (optional, required if $limitfrom is set).
|
|
* @return object moodle_recordset instance
|
|
* @throws dml_exception if error
|
|
*/
|
|
public function get_recordset_select($table, $select, array $params=null, $sort='', $fields='*', $limitfrom=0, $limitnum=0) {
|
|
$sql = "SELECT $fields FROM {".$table."}";
|
|
if ($select) {
|
|
$sql .= " WHERE $select";
|
|
}
|
|
if ($sort) {
|
|
$sql .= " ORDER BY $sort";
|
|
}
|
|
return $this->get_recordset_sql($sql, $params, $limitfrom, $limitnum);
|
|
}
|
|
|
|
/**
|
|
* Get a number of records as a moodle_recordset using a SQL statement.
|
|
*
|
|
* Since this method is a little less readable, use of it should be restricted to
|
|
* code where it's possible there might be large datasets being returned. For known
|
|
* small datasets use get_records_sql - it leads to simpler code.
|
|
*
|
|
* The return type is as for @see function get_recordset.
|
|
*
|
|
* @param string $sql the SQL select query to execute.
|
|
* @param array $params array of sql parameters
|
|
* @param int $limitfrom return a subset of records, starting at this point (optional, required if $limitnum is set).
|
|
* @param int $limitnum return a subset comprising this many records (optional, required if $limitfrom is set).
|
|
* @return object moodle_recordset instance
|
|
* @throws dml_exception if error
|
|
*/
|
|
public abstract function get_recordset_sql($sql, array $params=null, $limitfrom=0, $limitnum=0);
|
|
|
|
/**
|
|
* Get a number of records as an array of objects where all the given conditions met.
|
|
*
|
|
* If the query succeeds and returns at least one record, the
|
|
* return value is an array of objects, one object for each
|
|
* record found. The array key is the value from the first
|
|
* column of the result set. The object associated with that key
|
|
* has a member variable for each column of the results.
|
|
*
|
|
* @param string $table the table to query.
|
|
* @param array $conditions optional array $fieldname=>requestedvalue with AND in between
|
|
* @param string $sort an order to sort the results in (optional, a valid SQL ORDER BY parameter).
|
|
* @param string $fields a comma separated list of fields to return (optional, by default
|
|
* all fields are returned). The first field will be used as key for the
|
|
* array so must be a unique field such as 'id'.
|
|
* @param int $limitfrom return a subset of records, starting at this point (optional, required if $limitnum is set).
|
|
* @param int $limitnum return a subset comprising this many records (optional, required if $limitfrom is set).
|
|
* @return array of objects indexed by first column
|
|
* @throws dml_exception if error
|
|
*/
|
|
public function get_records($table, array $conditions=null, $sort='', $fields='*', $limitfrom=0, $limitnum=0) {
|
|
list($select, $params) = $this->where_clause($conditions);
|
|
return $this->get_records_select($table, $select, $params, $sort, $fields, $limitfrom, $limitnum);
|
|
}
|
|
|
|
/**
|
|
* Get a number of records as an array of objects where one field match one list of values.
|
|
*
|
|
* Return value as for @see function get_records.
|
|
*
|
|
* @param string $table The database table to be checked against.
|
|
* @param string $field The field to search
|
|
* @param string $values array of values
|
|
* @param string $sort Sort order (as valid SQL sort parameter)
|
|
* @param string $fields A comma separated list of fields to be returned from the chosen table. If specified,
|
|
* the first field should be a unique one such as 'id' since it will be used as a key in the associative
|
|
* array.
|
|
* @return array of objects indexed by first column
|
|
* @throws dml_exception if error
|
|
*/
|
|
public function get_records_list($table, $field, array $values, $sort='', $fields='*', $limitfrom=0, $limitnum=0) {
|
|
list($select, $params) = $this->where_clause_list($field, $values);
|
|
if (empty($select)) {
|
|
// nothing to return
|
|
return array();
|
|
}
|
|
return $this->get_records_select($table, $select, $params, $sort, $fields, $limitfrom, $limitnum);
|
|
}
|
|
|
|
/**
|
|
* Get a number of records as an array of objects which match a particular WHERE clause.
|
|
*
|
|
* Return value as for @see function get_records.
|
|
*
|
|
* @param string $table the table to query.
|
|
* @param string $select A fragment of SQL to be used in a where clause in the SQL call.
|
|
* @param array $params array of sql parameters
|
|
* @param string $sort an order to sort the results in (optional, a valid SQL ORDER BY parameter).
|
|
* @param string $fields a comma separated list of fields to return
|
|
* (optional, by default all fields are returned). The first field will be used as key for the
|
|
* array so must be a unique field such as 'id'.
|
|
* @param int $limitfrom return a subset of records, starting at this point (optional, required if $limitnum is set).
|
|
* @param int $limitnum return a subset comprising this many records (optional, required if $limitfrom is set).
|
|
* @return array of objects indexed by first column
|
|
* @throws dml_exception if error
|
|
*/
|
|
public function get_records_select($table, $select, array $params=null, $sort='', $fields='*', $limitfrom=0, $limitnum=0) {
|
|
if ($select) {
|
|
$select = "WHERE $select";
|
|
}
|
|
if ($sort) {
|
|
$sort = " ORDER BY $sort";
|
|
}
|
|
return $this->get_records_sql("SELECT $fields FROM {" . $table . "} $select $sort", $params, $limitfrom, $limitnum);
|
|
}
|
|
|
|
/**
|
|
* Get a number of records as an array of objects using a SQL statement.
|
|
*
|
|
* Return value as for @see function get_records.
|
|
*
|
|
* @param string $sql the SQL select query to execute. The first column of this SELECT statement
|
|
* must be a unique value (usually the 'id' field), as it will be used as the key of the
|
|
* returned array.
|
|
* @param array $params array of sql parameters
|
|
* @param int $limitfrom return a subset of records, starting at this point (optional, required if $limitnum is set).
|
|
* @param int $limitnum return a subset comprising this many records (optional, required if $limitfrom is set).
|
|
* @return array of objects indexed by first column
|
|
* @throws dml_exception if error
|
|
*/
|
|
public abstract function get_records_sql($sql, array $params=null, $limitfrom=0, $limitnum=0);
|
|
|
|
/**
|
|
* Get the first two columns from a number of records as an associative array where all the given conditions met.
|
|
*
|
|
* Arguments as for @see function get_recordset.
|
|
*
|
|
* If no errors occur the return value
|
|
* is an associative whose keys come from the first field of each record,
|
|
* and whose values are the corresponding second fields.
|
|
* False is returned if an error occurs.
|
|
*
|
|
* @param string $table the table to query.
|
|
* @param array $conditions optional array $fieldname=>requestedvalue with AND in between
|
|
* @param string $sort an order to sort the results in (optional, a valid SQL ORDER BY parameter).
|
|
* @param string $fields a comma separated list of fields to return - the number of fields should be 2!
|
|
* @param int $limitfrom return a subset of records, starting at this point (optional, required if $limitnum is set).
|
|
* @param int $limitnum return a subset comprising this many records (optional, required if $limitfrom is set).
|
|
* @return array an associative array
|
|
* @throws dml_exception if error
|
|
*/
|
|
public function get_records_menu($table, array $conditions=null, $sort='', $fields='*', $limitfrom=0, $limitnum=0) {
|
|
$menu = array();
|
|
if ($records = $this->get_records($table, $conditions, $sort, $fields, $limitfrom, $limitnum)) {
|
|
foreach ($records as $record) {
|
|
$record = (array)$record;
|
|
$key = array_shift($record);
|
|
$value = array_shift($record);
|
|
$menu[$key] = $value;
|
|
}
|
|
}
|
|
return $menu;
|
|
}
|
|
|
|
/**
|
|
* Get the first two columns from a number of records as an associative array which match a particular WHERE clause.
|
|
*
|
|
* Arguments as for @see function get_recordset_select.
|
|
* Return value as for @see function get_records_menu.
|
|
*
|
|
* @param string $table The database table to be checked against.
|
|
* @param string $select A fragment of SQL to be used in a where clause in the SQL call.
|
|
* @param array $params array of sql parameters
|
|
* @param string $sort Sort order (optional) - a valid SQL order parameter
|
|
* @param string $fields A comma separated list of fields to be returned from the chosen table - the number of fields should be 2!
|
|
* @param int $limitfrom return a subset of records, starting at this point (optional, required if $limitnum is set).
|
|
* @param int $limitnum return a subset comprising this many records (optional, required if $limitfrom is set).
|
|
* @return array an associative array
|
|
* @throws dml_exception if error
|
|
*/
|
|
public function get_records_select_menu($table, $select, array $params=null, $sort='', $fields='*', $limitfrom=0, $limitnum=0) {
|
|
$menu = array();
|
|
if ($records = $this->get_records_select($table, $select, $params, $sort, $fields, $limitfrom, $limitnum)) {
|
|
foreach ($records as $record) {
|
|
$record = (array)$record;
|
|
$key = array_shift($record);
|
|
$value = array_shift($record);
|
|
$menu[$key] = $value;
|
|
}
|
|
}
|
|
return $menu;
|
|
}
|
|
|
|
/**
|
|
* Get the first two columns from a number of records as an associative array using a SQL statement.
|
|
*
|
|
* Arguments as for @see function get_recordset_sql.
|
|
* Return value as for @see function get_records_menu.
|
|
*
|
|
* @param string $sql The SQL string you wish to be executed.
|
|
* @param array $params array of sql parameters
|
|
* @param int $limitfrom return a subset of records, starting at this point (optional, required if $limitnum is set).
|
|
* @param int $limitnum return a subset comprising this many records (optional, required if $limitfrom is set).
|
|
* @return array an associative array
|
|
* @throws dml_exception if error
|
|
*/
|
|
public function get_records_sql_menu($sql, array $params=null, $limitfrom=0, $limitnum=0) {
|
|
$menu = array();
|
|
if ($records = $this->get_records_sql($sql, $params, $limitfrom, $limitnum)) {
|
|
foreach ($records as $record) {
|
|
$record = (array)$record;
|
|
$key = array_shift($record);
|
|
$value = array_shift($record);
|
|
$menu[$key] = $value;
|
|
}
|
|
}
|
|
return $menu;
|
|
}
|
|
|
|
/**
|
|
* Get a single database record as an object where all the given conditions met.
|
|
*
|
|
* @param string $table The table to select from.
|
|
* @param array $conditions optional array $fieldname=>requestedvalue with AND in between
|
|
* @param string $fields A comma separated list of fields to be returned from the chosen table.
|
|
* @param int $strictness IGNORE_MISSING means compatible mode, false returned if record not found, debug message if more found;
|
|
* IGNORE_MULTIPLE means return first, ignore multiple records found(not recommended);
|
|
* MUST_EXIST means throw exception if no record or multiple records found
|
|
* @return mixed a fieldset object containing the first matching record, false or exception if error not found depending on mode
|
|
* @throws dml_exception if error
|
|
*/
|
|
public function get_record($table, array $conditions, $fields='*', $strictness=IGNORE_MISSING) {
|
|
list($select, $params) = $this->where_clause($conditions);
|
|
return $this->get_record_select($table, $select, $params, $fields, $strictness);
|
|
}
|
|
|
|
/**
|
|
* Get a single database record as an object which match a particular WHERE clause.
|
|
*
|
|
* @param string $table The database table to be checked against.
|
|
* @param string $select A fragment of SQL to be used in a where clause in the SQL call.
|
|
* @param array $params array of sql parameters
|
|
* @param int $strictness IGNORE_MISSING means compatible mode, false returned if record not found, debug message if more found;
|
|
* IGNORE_MULTIPLE means return first, ignore multiple records found(not recommended);
|
|
* MUST_EXIST means throw exception if no record or multiple records found
|
|
* @return mixed a fieldset object containing the first matching record, false or exception if error not found depending on mode
|
|
* @throws dml_exception if error
|
|
*/
|
|
public function get_record_select($table, $select, array $params=null, $fields='*', $strictness=IGNORE_MISSING) {
|
|
if ($select) {
|
|
$select = "WHERE $select";
|
|
}
|
|
try {
|
|
return $this->get_record_sql("SELECT $fields FROM {" . $table . "} $select", $params, $strictness);
|
|
} catch (dml_missing_record_exception $e) {
|
|
// create new exception which will contain correct table name
|
|
throw new dml_missing_record_exception($table, $e->sql, $e->params);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Get a single database record as an object using a SQL statement.
|
|
*
|
|
* The SQL statement should normally only return one record.
|
|
* It is recommended to use get_records_sql() if more matches possible!
|
|
*
|
|
* @param string $sql The SQL string you wish to be executed, should normally only return one record.
|
|
* @param array $params array of sql parameters
|
|
* @param int $strictness IGNORE_MISSING means compatible mode, false returned if record not found, debug message if more found;
|
|
* IGNORE_MULTIPLE means return first, ignore multiple records found(not recommended);
|
|
* MUST_EXIST means throw exception if no record or multiple records found
|
|
* @return mixed a fieldset object containing the first matching record, false or exception if error not found depending on mode
|
|
* @throws dml_exception if error
|
|
*/
|
|
public function get_record_sql($sql, array $params=null, $strictness=IGNORE_MISSING) {
|
|
$strictness = (int)$strictness; // we support true/false for BC reasons too
|
|
if ($strictness == IGNORE_MULTIPLE) {
|
|
$count = 1;
|
|
} else {
|
|
$count = 0;
|
|
}
|
|
if (!$records = $this->get_records_sql($sql, $params, 0, $count)) {
|
|
// not found
|
|
if ($strictness == MUST_EXIST) {
|
|
throw new dml_missing_record_exception('', $sql, $params);
|
|
}
|
|
return false;
|
|
}
|
|
|
|
if (count($records) > 1) {
|
|
if ($strictness == MUST_EXIST) {
|
|
throw new dml_multiple_records_exception($sql, $params);
|
|
}
|
|
debugging('Error: mdb->get_record() found more than one record!');
|
|
}
|
|
|
|
$return = reset($records);
|
|
return $return;
|
|
}
|
|
|
|
/**
|
|
* Get a single field value from a table record where all the given conditions met.
|
|
*
|
|
* @param string $table the table to query.
|
|
* @param string $return the field to return the value of.
|
|
* @param array $conditions optional array $fieldname=>requestedvalue with AND in between
|
|
* @param int $strictness IGNORE_MISSING means compatible mode, false returned if record not found, debug message if more found;
|
|
* IGNORE_MULTIPLE means return first, ignore multiple records found(not recommended);
|
|
* MUST_EXIST means throw exception if no record or multiple records found
|
|
* @return mixed the specified value false if not found
|
|
* @throws dml_exception if error
|
|
*/
|
|
public function get_field($table, $return, array $conditions, $strictness=IGNORE_MISSING) {
|
|
list($select, $params) = $this->where_clause($conditions);
|
|
return $this->get_field_select($table, $return, $select, $params, $strictness);
|
|
}
|
|
|
|
/**
|
|
* Get a single field value from a table record which match a particular WHERE clause.
|
|
*
|
|
* @param string $table the table to query.
|
|
* @param string $return the field to return the value of.
|
|
* @param string $select A fragment of SQL to be used in a where clause returning one row with one column
|
|
* @param array $params array of sql parameters
|
|
* @param int $strictness IGNORE_MISSING means compatible mode, false returned if record not found, debug message if more found;
|
|
* IGNORE_MULTIPLE means return first, ignore multiple records found(not recommended);
|
|
* MUST_EXIST means throw exception if no record or multiple records found
|
|
* @return mixed the specified value false if not found
|
|
* @throws dml_exception if error
|
|
*/
|
|
public function get_field_select($table, $return, $select, array $params=null, $strictness=IGNORE_MISSING) {
|
|
if ($select) {
|
|
$select = "WHERE $select";
|
|
}
|
|
try {
|
|
return $this->get_field_sql("SELECT $return FROM {" . $table . "} $select", $params, $strictness);
|
|
} catch (dml_missing_record_exception $e) {
|
|
// create new exception which will contain correct table name
|
|
throw new dml_missing_record_exception($table, $e->sql, $e->params);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Get a single field value (first field) using a SQL statement.
|
|
*
|
|
* @param string $table the table to query.
|
|
* @param string $return the field to return the value of.
|
|
* @param string $sql The SQL query returning one row with one column
|
|
* @param array $params array of sql parameters
|
|
* @param int $strictness IGNORE_MISSING means compatible mode, false returned if record not found, debug message if more found;
|
|
* IGNORE_MULTIPLE means return first, ignore multiple records found(not recommended);
|
|
* MUST_EXIST means throw exception if no record or multiple records found
|
|
* @return mixed the specified value false if not found
|
|
* @throws dml_exception if error
|
|
*/
|
|
public function get_field_sql($sql, array $params=null, $strictness=IGNORE_MISSING) {
|
|
if (!$record = $this->get_record_sql($sql, $params, $strictness)) {
|
|
return false;
|
|
}
|
|
|
|
$record = (array)$record;
|
|
return reset($record); // first column
|
|
}
|
|
|
|
/**
|
|
* Selects records and return values of chosen field as an array which match a particular WHERE clause.
|
|
*
|
|
* @param string $table the table to query.
|
|
* @param string $return the field we are intered in
|
|
* @param string $select A fragment of SQL to be used in a where clause in the SQL call.
|
|
* @param array $params array of sql parameters
|
|
* @return mixed array of values
|
|
* @throws dml_exception if error
|
|
*/
|
|
public function get_fieldset_select($table, $return, $select, array $params=null) {
|
|
if ($select) {
|
|
$select = "WHERE $select";
|
|
}
|
|
return $this->get_fieldset_sql("SELECT $return FROM {" . $table . "} $select", $params);
|
|
}
|
|
|
|
/**
|
|
* Selects records and return values (first field) as an array using a SQL statement.
|
|
*
|
|
* @param string $sql The SQL query
|
|
* @param array $params array of sql parameters
|
|
* @return mixed array of values
|
|
* @throws dml_exception if error
|
|
*/
|
|
public abstract function get_fieldset_sql($sql, array $params=null);
|
|
|
|
/**
|
|
* Insert new record into database, as fast as possible, no safety checks, lobs not supported.
|
|
* @param string $table name
|
|
* @param mixed $params data record as object or array
|
|
* @param bool $returnit return it of inserted record
|
|
* @param bool $bulk true means repeated inserts expected
|
|
* @param bool $customsequence true if 'id' included in $params, disables $returnid
|
|
* @return mixed true or new id
|
|
* @throws dml_exception if error
|
|
*/
|
|
public abstract function insert_record_raw($table, $params, $returnid=true, $bulk=false, $customsequence=false);
|
|
|
|
/**
|
|
* Insert a record into a table and return the "id" field if required.
|
|
*
|
|
* Some conversions and safety checks are carried out. Lobs are supported.
|
|
* If the return ID isn't required, then this just reports success as true/false.
|
|
* $data is an object containing needed data
|
|
* @param string $table The database table to be inserted into
|
|
* @param object $data A data object with values for one or more fields in the record
|
|
* @param bool $returnid Should the id of the newly created record entry be returned? If this option is not requested then true/false is returned.
|
|
* @return mixed true or new id
|
|
* @throws dml_exception if error
|
|
*/
|
|
public abstract function insert_record($table, $dataobject, $returnid=true, $bulk=false);
|
|
|
|
/**
|
|
* Import a record into a table, id field is required.
|
|
* Safety checks are NOT carried out. Lobs are supported.
|
|
*
|
|
* @param string $table name of database table to be inserted into
|
|
* @param object $dataobject A data object with values for one or more fields in the record
|
|
* @return bool true
|
|
* @throws dml_exception if error
|
|
*/
|
|
public abstract function import_record($table, $dataobject);
|
|
|
|
/**
|
|
* Update record in database, as fast as possible, no safety checks, lobs not supported.
|
|
* @param string $table name
|
|
* @param mixed $params data record as object or array
|
|
* @param bool true means repeated updates expected
|
|
* @return bool true
|
|
* @throws dml_exception if error
|
|
*/
|
|
public abstract function update_record_raw($table, $params, $bulk=false);
|
|
|
|
/**
|
|
* Update a record in a table
|
|
*
|
|
* $dataobject is an object containing needed data
|
|
* Relies on $dataobject having a variable "id" to
|
|
* specify the record to update
|
|
*
|
|
* @param string $table The database table to be checked against.
|
|
* @param object $dataobject An object with contents equal to fieldname=>fieldvalue. Must have an entry for 'id' to map to the table specified.
|
|
* @param bool true means repeated updates expected
|
|
* @return bool true
|
|
* @throws dml_exception if error
|
|
*/
|
|
public abstract function update_record($table, $dataobject, $bulk=false);
|
|
|
|
|
|
/**
|
|
* Set a single field in every table record where all the given conditions met.
|
|
*
|
|
* @param string $table The database table to be checked against.
|
|
* @param string $newfield the field to set.
|
|
* @param string $newvalue the value to set the field to.
|
|
* @param array $conditions optional array $fieldname=>requestedvalue with AND in between
|
|
* @return bool true
|
|
* @throws dml_exception if error
|
|
*/
|
|
public function set_field($table, $newfield, $newvalue, array $conditions=null) {
|
|
list($select, $params) = $this->where_clause($conditions);
|
|
return $this->set_field_select($table, $newfield, $newvalue, $select, $params);
|
|
}
|
|
|
|
/**
|
|
* Set a single field in every table record which match a particular WHERE clause.
|
|
*
|
|
* @param string $table The database table to be checked against.
|
|
* @param string $newfield the field to set.
|
|
* @param string $newvalue the value to set the field to.
|
|
* @param string $select A fragment of SQL to be used in a where clause in the SQL call.
|
|
* @param array $params array of sql parameters
|
|
* @return bool true
|
|
* @throws dml_exception if error
|
|
*/
|
|
public abstract function set_field_select($table, $newfield, $newvalue, $select, array $params=null);
|
|
|
|
|
|
/**
|
|
* Count the records in a table where all the given conditions met.
|
|
*
|
|
* @param string $table The table to query.
|
|
* @param array $conditions optional array $fieldname=>requestedvalue with AND in between
|
|
* @return int The count of records returned from the specified criteria.
|
|
* @throws dml_exception if error
|
|
*/
|
|
public function count_records($table, array $conditions=null) {
|
|
list($select, $params) = $this->where_clause($conditions);
|
|
return $this->count_records_select($table, $select, $params);
|
|
}
|
|
|
|
/**
|
|
* Count the records in a table which match a particular WHERE clause.
|
|
*
|
|
* @param string $table The database table to be checked against.
|
|
* @param string $select A fragment of SQL to be used in a WHERE clause in the SQL call.
|
|
* @param array $params array of sql parameters
|
|
* @param string $countitem The count string to be used in the SQL call. Default is COUNT('x').
|
|
* @return int The count of records returned from the specified criteria.
|
|
* @throws dml_exception if error
|
|
*/
|
|
public function count_records_select($table, $select, array $params=null, $countitem="COUNT('x')") {
|
|
if ($select) {
|
|
$select = "WHERE $select";
|
|
}
|
|
return $this->count_records_sql("SELECT $countitem FROM {" . $table . "} $select", $params);
|
|
}
|
|
|
|
/**
|
|
* Get the result of a SQL SELECT COUNT(...) query.
|
|
*
|
|
* Given a query that counts rows, return that count. (In fact,
|
|
* given any query, return the first field of the first record
|
|
* returned. However, this method should only be used for the
|
|
* intended purpose.) If an error occurs, 0 is returned.
|
|
*
|
|
* @param string $sql The SQL string you wish to be executed.
|
|
* @param array $params array of sql parameters
|
|
* @return int the count
|
|
* @throws dml_exception if error
|
|
*/
|
|
public function count_records_sql($sql, array $params=null) {
|
|
if ($count = $this->get_field_sql($sql, $params)) {
|
|
return $count;
|
|
} else {
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Test whether a record exists in a table where all the given conditions met.
|
|
*
|
|
* The record to test is specified by giving up to three fields that must
|
|
* equal the corresponding values.
|
|
*
|
|
* @param string $table The table to check.
|
|
* @param array $conditions optional array $fieldname=>requestedvalue with AND in between
|
|
* @return bool true if a matching record exists, else false.
|
|
* @throws dml_exception if error
|
|
*/
|
|
public function record_exists($table, array $conditions) {
|
|
list($select, $params) = $this->where_clause($conditions);
|
|
return $this->record_exists_select($table, $select, $params);
|
|
}
|
|
|
|
/**
|
|
* Test whether any records exists in a table which match a particular WHERE clause.
|
|
*
|
|
* @param string $table The database table to be checked against.
|
|
* @param string $select A fragment of SQL to be used in a WHERE clause in the SQL call.
|
|
* @param array $params array of sql parameters
|
|
* @return bool true if a matching record exists, else false.
|
|
* @throws dml_exception if error
|
|
*/
|
|
public function record_exists_select($table, $select, array $params=null) {
|
|
if ($select) {
|
|
$select = "WHERE $select";
|
|
}
|
|
return $this->record_exists_sql("SELECT 'x' FROM {" . $table . "} $select", $params);
|
|
}
|
|
|
|
/**
|
|
* Test whether a SQL SELECT statement returns any records.
|
|
*
|
|
* This function returns true if the SQL statement executes
|
|
* without any errors and returns at least one record.
|
|
*
|
|
* @param string $sql The SQL statement to execute.
|
|
* @param array $params array of sql parameters
|
|
* @return bool true if the SQL executes without errors and returns at least one record.
|
|
* @throws dml_exception if error
|
|
*/
|
|
public function record_exists_sql($sql, array $params=null) {
|
|
if ($mrs = $this->get_recordset_sql($sql, $params, 0, 1)) {
|
|
$return = $mrs->valid();
|
|
$mrs->close();
|
|
return $return;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* Delete the records from a table where all the given conditions met.
|
|
* If conditions not specified, table is truncated.
|
|
*
|
|
* @param string $table the table to delete from.
|
|
* @param array $conditions optional array $fieldname=>requestedvalue with AND in between
|
|
* @return bool true.
|
|
* @throws dml_exception if error
|
|
*/
|
|
public function delete_records($table, array $conditions=null) {
|
|
if (is_null($conditions)) {
|
|
return $this->execute("TRUNCATE TABLE {".$table."}");
|
|
}
|
|
list($select, $params) = $this->where_clause($conditions);
|
|
return $this->delete_records_select($table, $select, $params);
|
|
}
|
|
|
|
/**
|
|
* Delete the records from a table where one field match one list of values.
|
|
*
|
|
* @param string $table the table to delete from.
|
|
* @param string $field The field to search
|
|
* @param string $values array of values
|
|
* @return bool true.
|
|
* @throws dml_exception if error
|
|
*/
|
|
public function delete_records_list($table, $field, array $values) {
|
|
list($select, $params) = $this->where_clause_list($field, $values);
|
|
if (empty($select)) {
|
|
// nothing to delete
|
|
return true;
|
|
}
|
|
return $this->delete_records_select($table, $select, $params);
|
|
}
|
|
|
|
/**
|
|
* Delete one or more records from a table which match a particular WHERE clause.
|
|
*
|
|
* @param string $table The database table to be checked against.
|
|
* @param string $select A fragment of SQL to be used in a where clause in the SQL call (used to define the selection criteria).
|
|
* @param array $params array of sql parameters
|
|
* @return bool true.
|
|
* @throws dml_exception if error
|
|
*/
|
|
public abstract function delete_records_select($table, $select, array $params=null);
|
|
|
|
|
|
|
|
/// sql constructs
|
|
/**
|
|
* Returns the FROM clause required by some DBs in all SELECT statements.
|
|
*
|
|
* To be used in queries not having FROM clause to provide cross_db
|
|
* Most DBs don't need it, hence the default is ''
|
|
*/
|
|
public function sql_null_from_clause() {
|
|
return '';
|
|
}
|
|
|
|
/**
|
|
* Returns the SQL text to be used in order to perform one bitwise AND operation
|
|
* between 2 integers.
|
|
*
|
|
* NOTE: The SQL result is a number and can not be used directly in
|
|
* SQL condition, please compare it to some number to get a bool!!
|
|
*
|
|
* @param integer int1 first integer in the operation
|
|
* @param integer int2 second integer in the operation
|
|
* @return string the piece of SQL code to be used in your statement
|
|
*/
|
|
public function sql_bitand($int1, $int2) {
|
|
return '((' . $int1 . ') & (' . $int2 . '))';
|
|
}
|
|
|
|
/**
|
|
* Returns the SQL text to be used in order to perform one bitwise NOT operation
|
|
* with 1 integer.
|
|
*
|
|
* @param integer int1 integer in the operation
|
|
* @return string the piece of SQL code to be used in your statement.
|
|
*/
|
|
public function sql_bitnot($int1) {
|
|
return '(~(' . $int1 . '))';
|
|
}
|
|
|
|
/**
|
|
* Returns the SQL text to be used in order to perform one bitwise OR operation
|
|
* between 2 integers.
|
|
*
|
|
* NOTE: The SQL result is a number and can not be used directly in
|
|
* SQL condition, please compare it to some number to get a bool!!
|
|
*
|
|
* @param integer int1 first integer in the operation
|
|
* @param integer int2 second integer in the operation
|
|
* @return string the piece of SQL code to be used in your statement.
|
|
*/
|
|
public function sql_bitor($int1, $int2) {
|
|
return '((' . $int1 . ') | (' . $int2 . '))';
|
|
}
|
|
|
|
/**
|
|
* Returns the SQL text to be used in order to perform one bitwise XOR operation
|
|
* between 2 integers.
|
|
*
|
|
* NOTE: The SQL result is a number and can not be used directly in
|
|
* SQL condition, please compare it to some number to get a bool!!
|
|
*
|
|
* @param integer int1 first integer in the operation
|
|
* @param integer int2 second integer in the operation
|
|
* @return string the piece of SQL code to be used in your statement.
|
|
*/
|
|
public function sql_bitxor($int1, $int2) {
|
|
return '((' . $int1 . ') ^ (' . $int2 . '))';
|
|
}
|
|
|
|
/**
|
|
* Returns the SQL text to be used in order to perform module '%'
|
|
* operation - remainder after division
|
|
*
|
|
* @param integer int1 first integer in the operation
|
|
* @param integer int2 second integer in the operation
|
|
* @return string the piece of SQL code to be used in your statement.
|
|
*/
|
|
public function sql_modulo($int1, $int2) {
|
|
return '((' . $int1 . ') % (' . $int2 . '))';
|
|
}
|
|
|
|
/**
|
|
* Returns the correct CEIL expression applied to fieldname.
|
|
*
|
|
* @param string fieldname the field (or expression) we are going to ceil
|
|
* @return string the piece of SQL code to be used in your ceiling statement
|
|
* Most DB use CEIL(), hence it's the default.
|
|
*/
|
|
public function sql_ceil($fieldname) {
|
|
return ' CEIL(' . $fieldname . ')';
|
|
}
|
|
|
|
/**
|
|
* Returns the SQL to be used in order to CAST one CHAR column to INTEGER.
|
|
*
|
|
* Be aware that the CHAR column you're trying to cast contains really
|
|
* int values or the RDBMS will throw an error!
|
|
*
|
|
* @param string fieldname the name of the field to be casted
|
|
* @param boolean text to specify if the original column is one TEXT (CLOB) column (true). Defaults to false.
|
|
* @return string the piece of SQL code to be used in your statement.
|
|
*/
|
|
public function sql_cast_char2int($fieldname, $text=false) {
|
|
return ' ' . $fieldname . ' ';
|
|
}
|
|
|
|
/**
|
|
* Returns the SQL to be used in order to CAST one CHAR column to REAL number.
|
|
*
|
|
* Be aware that the CHAR column you're trying to cast contains really
|
|
* numbers or the RDBMS will throw an error!
|
|
*
|
|
* @param string fieldname the name of the field to be casted
|
|
* @param boolean text to specify if the original column is one TEXT (CLOB) column (true). Defaults to false.
|
|
* @return string the piece of SQL code to be used in your statement.
|
|
*/
|
|
public function sql_cast_char2real($fieldname, $text=false) {
|
|
return ' ' . $fieldname . ' ';
|
|
}
|
|
|
|
/**
|
|
* Returns the SQL to be used in order to an UNSIGNED INTEGER column to SIGNED.
|
|
*
|
|
* (Only MySQL needs this. MySQL things that 1 * -1 = 18446744073709551615
|
|
* if the 1 comes from an unsigned column).
|
|
*
|
|
* @param string fieldname the name of the field to be cast
|
|
* @return string the piece of SQL code to be used in your statement.
|
|
*/
|
|
public function sql_cast_2signed($fieldname) {
|
|
return ' ' . $fieldname . ' ';
|
|
}
|
|
|
|
/**
|
|
* Returns the SQL text to be used to compare one TEXT (clob) column with
|
|
* one varchar column, because some RDBMS doesn't support such direct
|
|
* comparisons.
|
|
*
|
|
* @param string fieldname the name of the TEXT field we need to order by
|
|
* @param string number of chars to use for the ordering (defaults to 32)
|
|
* @return string the piece of SQL code to be used in your statement.
|
|
*/
|
|
public function sql_compare_text($fieldname, $numchars=32) {
|
|
return $this->sql_order_by_text($fieldname, $numchars);
|
|
}
|
|
|
|
/**
|
|
* Returns the proper SQL to do LIKE in a case-insensitive way.
|
|
*
|
|
* Note the LIKE are case sensitive for Oracle. Oracle 10g is required to use
|
|
* the case insensitive search using regexp_like() or NLS_COMP=LINGUISTIC :-(
|
|
* See http://docs.moodle.org/en/XMLDB_Problems#Case-insensitive_searches
|
|
*
|
|
* @return string
|
|
*/
|
|
public function sql_ilike() {
|
|
return 'LIKE';
|
|
}
|
|
|
|
/**
|
|
* Returns the proper SQL to do CONCAT between the elements passed
|
|
* Can take many parameters
|
|
*
|
|
* @param string $element
|
|
* @return string
|
|
*/
|
|
public abstract function sql_concat();
|
|
|
|
/**
|
|
* Returns the proper SQL to do CONCAT between the elements passed
|
|
* with a given separator
|
|
*
|
|
* @param string $separator
|
|
* @param array $elements
|
|
* @return string
|
|
*/
|
|
public abstract function sql_concat_join($separator="' '", $elements=array());
|
|
|
|
/**
|
|
* Returns the proper SQL (for the dbms in use) to concatenate $firstname and $lastname
|
|
* TODO: Does this really need to be here? Eloy 20070727.
|
|
*
|
|
* @param string $firstname User's first name
|
|
* @param string $lastname User's last name
|
|
* @return string
|
|
*/
|
|
function sql_fullname($first='firstname', $last='lastname') {
|
|
return $this->sql_concat($first, "' '", $last);
|
|
}
|
|
|
|
/**
|
|
* Returns the SQL text to be used to order by one TEXT (clob) column, because
|
|
* some RDBMS doesn't support direct ordering of such fields.
|
|
*
|
|
* Note that the use or queries being ordered by TEXT columns must be minimised,
|
|
* because it's really slooooooow.
|
|
* @param string fieldname the name of the TEXT field we need to order by
|
|
* @param string number of chars to use for the ordering (defaults to 32)
|
|
* @return string the piece of SQL code to be used in your statement.
|
|
*/
|
|
public function sql_order_by_text($fieldname, $numchars=32) {
|
|
return $fieldname;
|
|
}
|
|
|
|
/**
|
|
* Returns the SQL text to be used to calculate the length in characters of one expression.
|
|
* @param string fieldname or expression to calculate its length in characters.
|
|
* @return string the piece of SQL code to be used in the statement.
|
|
*/
|
|
public function sql_length($fieldname) {
|
|
return ' LENGTH(' . $fieldname . ')';
|
|
}
|
|
|
|
/**
|
|
* Returns the proper substr() SQL text used to extract substrings from DB
|
|
* NOTE: this was originally returning only function name
|
|
*
|
|
* @param string $expr some string field, no aggregates
|
|
* @param mixed $start integer or expression evaluating to int (1 based value; first char has index 1)
|
|
* @param mixed $length optional integer or expression evaluating to int
|
|
* @return string sql fragment
|
|
*/
|
|
public function sql_substr($expr, $start, $length=false) {
|
|
if (count(func_get_args()) < 2) {
|
|
throw new coding_exception('moodle_database::sql_substr() requires at least two parameters', 'Originally this function was only returning name of SQL substring function, it now requires all parameters.');
|
|
}
|
|
if ($length === false) {
|
|
return "SUBSTR($expr, $start)";
|
|
} else {
|
|
return "SUBSTR($expr, $start, $length)";
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Returns the SQL for returning searching one string for the location of another.
|
|
* Note, there is no guarantee which order $needle, $haystack will be in
|
|
* the resulting SQL, so when using this method, and both arguments contain
|
|
* placeholders, you should use named placeholders.
|
|
* @param string $needle the SQL expression that will be searched for.
|
|
* @param string $haystack the SQL expression that will be searched in.
|
|
* @return string the required SQL
|
|
*/
|
|
public function sql_position($needle, $haystack) {
|
|
// Implementation using standard SQL.
|
|
return "POSITION(($needle) IN ($haystack))";
|
|
}
|
|
|
|
/**
|
|
* Returns the empty string char used by every supported DB. To be used when
|
|
* we are searching for that values in our queries. Only Oracle uses this
|
|
* for now (will be out, once we migrate to proper NULLs if that days arrives)
|
|
*/
|
|
function sql_empty() {
|
|
return '';
|
|
}
|
|
|
|
/**
|
|
* Returns the proper SQL to know if one field is empty.
|
|
*
|
|
* Note that the function behavior strongly relies on the
|
|
* parameters passed describing the field so, please, be accurate
|
|
* when specifying them.
|
|
*
|
|
* Also, note that this function is not suitable to look for
|
|
* fields having NULL contents at all. It's all for empty values!
|
|
*
|
|
* This function should be applied in all the places where conditions of
|
|
* the type:
|
|
*
|
|
* ... AND fieldname = '';
|
|
*
|
|
* are being used. Final result should be:
|
|
*
|
|
* ... AND ' . sql_isempty('tablename', 'fieldname', true/false, true/false);
|
|
*
|
|
* (see parameters description below)
|
|
*
|
|
* @param string $tablename name of the table (without prefix). Not used for now but can be
|
|
* necessary in the future if we want to use some introspection using
|
|
* meta information against the DB. /// TODO ///
|
|
* @param string $fieldname name of the field we are going to check
|
|
* @param boolean $nullablefield to specify if the field us nullable (true) or no (false) in the DB
|
|
* @param boolean $textfield to specify if it is a text (also called clob) field (true) or a varchar one (false)
|
|
* @return string the sql code to be added to check for empty values
|
|
*/
|
|
public function sql_isempty($tablename, $fieldname, $nullablefield, $textfield) {
|
|
return " ($fieldname = '') ";
|
|
}
|
|
|
|
/**
|
|
* Returns the proper SQL to know if one field is not empty.
|
|
*
|
|
* Note that the function behavior strongly relies on the
|
|
* parameters passed describing the field so, please, be accurate
|
|
* when specifying them.
|
|
*
|
|
* This function should be applied in all the places where conditions of
|
|
* the type:
|
|
*
|
|
* ... AND fieldname != '';
|
|
*
|
|
* are being used. Final result should be:
|
|
*
|
|
* ... AND ' . sql_isnotempty('tablename', 'fieldname', true/false, true/false);
|
|
*
|
|
* (see parameters description below)
|
|
*
|
|
* @param string $tablename name of the table (without prefix). Not used for now but can be
|
|
* necessary in the future if we want to use some introspection using
|
|
* meta information against the DB. /// TODO ///
|
|
* @param string $fieldname name of the field we are going to check
|
|
* @param boolean $nullablefield to specify if the field us nullable (true) or no (false) in the DB
|
|
* @param boolean $textfield to specify if it is a text (also called clob) field (true) or a varchar one (false)
|
|
* @return string the sql code to be added to check for non empty values
|
|
*/
|
|
public function sql_isnotempty($tablename, $fieldname, $nullablefield, $textfield) {
|
|
return ' ( NOT ' . $this->sql_isempty($tablename, $fieldname, $nullablefield, $textfield) . ') ';
|
|
}
|
|
|
|
/**
|
|
* Does this driver suppoer regex syntax when searching
|
|
*/
|
|
public function sql_regex_supported() {
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* Return regex positive or negative match sql
|
|
* @param bool $positivematch
|
|
* @return string or empty if not supported
|
|
*/
|
|
public function sql_regex($positivematch=true) {
|
|
return '';
|
|
}
|
|
|
|
/// transactions
|
|
|
|
/**
|
|
* Are transactions supported?
|
|
* It is not responsible to run productions servers
|
|
* on databases without transaction support ;-)
|
|
*
|
|
* Override in driver if needed.
|
|
*
|
|
* @return bool
|
|
*/
|
|
protected function transactions_supported() {
|
|
// protected for now, this might be changed to public if really necessary
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* Returns true if transaction in progress
|
|
* @return bool
|
|
*/
|
|
public function is_transaction_started() {
|
|
return !empty($this->transactions);
|
|
}
|
|
|
|
/**
|
|
* Throws exception if transaction in progress.
|
|
* This test does not force rollback of active transactions.
|
|
* @return void
|
|
*/
|
|
public function transactions_forbidden() {
|
|
if ($this->is_transaction_started()) {
|
|
throw new dml_transaction_exception('This code can not be excecuted in transaction');
|
|
}
|
|
}
|
|
|
|
/**
|
|
* On DBs that support it, switch to transaction mode and begin a transaction
|
|
* you'll need to ensure you call allow_commit() on the returned object
|
|
* or your changes *will* be lost.
|
|
*
|
|
* this is _very_ useful for massive updates
|
|
*
|
|
* Delegated database transactions can be nested, but only one actual database
|
|
* transaction is used for the outer-most delegated transaction. This method
|
|
* returns a transaction object which you should keep until the end of the
|
|
* delegated transaction. The actual database transaction will
|
|
* only be committed if all the nested delegated transactions commit
|
|
* successfully. If any part of the transaction rolls back then the whole
|
|
* thing is rolled back.
|
|
*
|
|
* @return moodle_transaction
|
|
*/
|
|
public function start_delegated_transaction() {
|
|
$transaction = new moodle_transaction($this);
|
|
$this->transactions[] = $transaction;
|
|
if (count($this->transactions) == 1) {
|
|
$this->begin_transaction();
|
|
}
|
|
return $transaction;
|
|
}
|
|
|
|
/**
|
|
* Driver specific start of real database transaction,
|
|
* this can not be used directly in code.
|
|
* @return void
|
|
*/
|
|
protected abstract function begin_transaction();
|
|
|
|
/**
|
|
* Indicates delegated transaction finished successfully.
|
|
* The real database transaction is committed only if
|
|
* all delegated transactions committed.
|
|
* @return void
|
|
*/
|
|
public function commit_delegated_transaction(moodle_transaction $transaction) {
|
|
if ($transaction->is_disposed()) {
|
|
throw new dml_transaction_exception('Transactions already disposed', $transaction);
|
|
}
|
|
// mark as disposed so that it can not be used again
|
|
$transaction->dispose();
|
|
|
|
if (empty($this->transactions)) {
|
|
throw new dml_transaction_exception('Transaction not started', $transaction);
|
|
}
|
|
|
|
if ($this->force_rollback) {
|
|
throw new dml_transaction_exception('Tried to commit transaction after lower level rollback', $transaction);
|
|
}
|
|
|
|
if ($transaction !== $this->transactions[count($this->transactions) - 1]) {
|
|
// one incorrect commit at any level rollbacks everything
|
|
$this->force_rollback = true;
|
|
throw new dml_transaction_exception('Invalid transaction commit attempt', $transaction);
|
|
}
|
|
|
|
if (count($this->transactions) == 1) {
|
|
// only commit the top most level
|
|
$this->commit_transaction();
|
|
}
|
|
array_pop($this->transactions);
|
|
}
|
|
|
|
/**
|
|
* Driver specific commit of real database transaction,
|
|
* this can not be used directly in code.
|
|
* @return void
|
|
*/
|
|
protected abstract function commit_transaction();
|
|
|
|
/**
|
|
* Call when delegated transaction failed, this rolls back
|
|
* all delegated transactions up to the top most level.
|
|
*
|
|
* In many cases you do not need to call this method manually,
|
|
* because all open delegated transactions are rolled back
|
|
* automatically if exceptions not caught.
|
|
*
|
|
* @param moodle_transaction $transaction
|
|
* @param Exception $e exception that caused the problem
|
|
* @return does not return, exception is rethrown
|
|
*/
|
|
public function rollback_delegated_transaction(moodle_transaction $transaction, Exception $e) {
|
|
if ($transaction->is_disposed()) {
|
|
throw new dml_transaction_exception('Transactions already disposed', $transaction);
|
|
}
|
|
// mark as disposed so that it can not be used again
|
|
$transaction->dispose();
|
|
|
|
// one rollback at any level rollbacks everything
|
|
$this->force_rollback = true;
|
|
|
|
if (empty($this->transactions) or $transaction !== $this->transactions[count($this->transactions) - 1]) {
|
|
// this may or may not be a coding problem, better just rethrow the exception,
|
|
// because we do not want to loose the original $e
|
|
throw $e;
|
|
}
|
|
|
|
if (count($this->transactions) == 1) {
|
|
// only rollback the top most level
|
|
$this->rollback_transaction();
|
|
}
|
|
array_pop($this->transactions);
|
|
if (empty($this->transactions)) {
|
|
// finally top most level rolled back
|
|
$this->force_rollback = false;
|
|
}
|
|
throw $e;
|
|
}
|
|
|
|
/**
|
|
* Driver specific abort of real database transaction,
|
|
* this can not be used directly in code.
|
|
* @return void
|
|
*/
|
|
protected abstract function rollback_transaction();
|
|
|
|
/**
|
|
* Force rollback of all delegated transaction.
|
|
* Does not trow any exceptions and does not log anything.
|
|
*
|
|
* This method should be used only from default exception handlers and other
|
|
* core code.
|
|
*
|
|
* @return void
|
|
*/
|
|
public function force_transaction_rollback() {
|
|
if ($this->transactions) {
|
|
try {
|
|
$this->rollback_transaction();
|
|
} catch (dml_exception $e) {
|
|
// ignore any sql errors here, the connection might be broken
|
|
}
|
|
}
|
|
|
|
// now enable transactions again
|
|
$this->transactions = array(); // unfortunately all unfinished exceptions are kept in memory
|
|
$this->force_rollback = false;
|
|
}
|
|
|
|
/// session locking
|
|
/**
|
|
* Is session lock supported in this driver?
|
|
* @return bool
|
|
*/
|
|
public function session_lock_supported() {
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* Obtain session lock
|
|
* @param int $rowid id of the row with session record
|
|
* @return success
|
|
*/
|
|
public function get_session_lock($rowid) {
|
|
$this->used_for_db_sessions = true;
|
|
}
|
|
|
|
/**
|
|
* Release session lock
|
|
* @param int $rowid id of the row with session record
|
|
* @return success
|
|
*/
|
|
public function release_session_lock($rowid) {
|
|
}
|
|
|
|
/// performance and logging
|
|
/**
|
|
* Returns number of reads done by this database
|
|
* @return int
|
|
*/
|
|
public function perf_get_reads() {
|
|
return $this->reads;
|
|
}
|
|
|
|
/**
|
|
* Returns number of writes done by this database
|
|
* @return int
|
|
*/
|
|
public function perf_get_writes() {
|
|
return $this->writes;
|
|
}
|
|
|
|
/**
|
|
* Returns number of queries done by this database
|
|
* @return int
|
|
*/
|
|
public function perf_get_queries() {
|
|
return $this->writes + $this->reads;
|
|
}
|
|
}
|