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moodle/lib/dmllib.php
stronk7 83a78d9d17 PHPDoc update.
2006-09-10 18:37:57 +00:00

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<?php // $Id$
///////////////////////////////////////////////////////////////////////////
// //
// NOTICE OF COPYRIGHT //
// //
// Moodle - Modular Object-Oriented Dynamic Learning Environment //
// http://moodle.com //
// //
// Copyright (C) 2001-3001 Martin Dougiamas http://dougiamas.com //
// //
// This program is free software; you can redistribute it and/or modify //
// it under the terms of the GNU General Public License as published by //
// the Free Software Foundation; either version 2 of the License, or //
// (at your option) any later version. //
// //
// This program is distributed in the hope that it will be useful, //
// but WITHOUT ANY WARRANTY; without even the implied warranty of //
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the //
// GNU General Public License for more details: //
// //
// http://www.gnu.org/copyleft/gpl.html //
// //
///////////////////////////////////////////////////////////////////////////
/// This library contains all the Data Manipulation Language (DML) functions
/// used to interact with the DB. All the dunctions in this library must be
/// generic and work against the major number of RDBMS possible. This is the
/// list of currently supported and tested DBs: mysql, postresql, mssql, oracle
/// This library is automatically included by Moodle core so you never need to
/// include it yourself.
/// For more info about the functions available in this library, please visit:
/// http://docs.moodle.org/en/DML_functions
/// (feel free to modify, improve and document such page, thanks!)
/// GLOBAL CONSTANTS /////////////////////////////////////////////////////////
$empty_rs_cache = array(); // Keeps copies of the recordsets used in one invocation
/// FUNCTIONS FOR DATABASE HANDLING ////////////////////////////////
/**
* Execute a given sql command string
*
* Completely general function - it just runs some SQL and reports success.
*
* @uses $db
* @param string $command The sql string you wish to be executed.
* @param bool $feedback Set this argument to true if the results generated should be printed. Default is true.
* @return string
*/
function execute_sql($command, $feedback=true) {
/// Completely general function - it just runs some SQL and reports success.
global $db, $CFG;
$olddebug = $db->debug;
if (!$feedback) {
$db->debug = false;
}
$empty_rs_cache = array(); // Clear out the cache, just in case changes were made to table structures
if (defined('MDL_PERFDB')) { global $PERF ; $PERF->dbqueries++; };
$result = $db->Execute($command);
$db->debug = $olddebug;
if ($result) {
if ($feedback) {
notify(get_string('success'), 'notifysuccess');
}
return true;
} else {
if ($feedback) {
notify('<strong>' . get_string('error') . '</strong>');
}
if (!empty($CFG->dblogerror)) {
$debug=array_shift(debug_backtrace());
error_log("SQL ".$db->ErrorMsg()." in {$debug['file']} on line {$debug['line']}. STATEMENT: $command");
}
return false;
}
}
/**
* on DBs that support it, switch to transaction mode and begin a transaction
* you'll need to ensure you call commit_sql() or your changes *will* be lost
* this is _very_ useful for massive updates
*/
function begin_sql() {
/// Completely general function - it just runs some SQL and reports success.
global $CFG;
if ($CFG->dbtype === 'postgres7') {
return execute_sql('BEGIN', false);
}
return true;
}
/**
* on DBs that support it, commit the transaction
*/
function rollback_sql() {
/// Completely general function - it just runs some SQL and reports success.
global $CFG;
if ($CFG->dbtype === 'postgres7') {
return execute_sql('ROLLBACK', false);
}
return true;
}
/**
* returns db specific uppercase function
* @deprecated Moodle 1.7 because all the RDBMS use upper()
*/
function db_uppercase() {
return "upper";
}
/**
* returns db specific lowercase function
* @deprecated Moodle 1.7 because all the RDBMS use lower()
*/
function db_lowercase() {
return "lower";
}
/**
* on DBs that support it, commit the transaction
*/
function commit_sql() {
/// Completely general function - it just runs some SQL and reports success.
global $CFG;
if ($CFG->dbtype === 'postgres7') {
return execute_sql('COMMIT', false);
}
return true;
}
/**
* Run an arbitrary sequence of semicolon-delimited SQL commands
*
* Assumes that the input text (file or string) consists of
* a number of SQL statements ENDING WITH SEMICOLONS. The
* semicolons MUST be the last character in a line.
* Lines that are blank or that start with "#" or "--" (postgres) are ignored.
* Only tested with mysql dump files (mysqldump -p -d moodle)
*
* @uses $CFG
* @param string $sqlfile The path where a file with sql commands can be found on the server.
* @param string $sqlstring If no path is supplied then a string with semicolon delimited sql
* commands can be supplied in this argument.
* @return bool Returns true if databse was modified successfully.
*/
function modify_database($sqlfile='', $sqlstring='') {
global $CFG;
$success = true; // Let's be optimistic
if (!empty($sqlfile)) {
if (!is_readable($sqlfile)) {
$success = false;
echo '<p>Tried to modify database, but "'. $sqlfile .'" doesn\'t exist!</p>';
return $success;
} else {
$lines = file($sqlfile);
}
} else {
$sqlstring = trim($sqlstring);
if ($sqlstring{strlen($sqlstring)-1} != ";") {
$sqlstring .= ";"; // add it in if it's not there.
}
$lines[] = $sqlstring;
}
$command = '';
foreach ($lines as $line) {
$line = rtrim($line);
$length = strlen($line);
if ($length and $line[0] <> '#' and $line[0].$line[1] <> '--') {
if (substr($line, $length-1, 1) == ';') {
$line = substr($line, 0, $length-1); // strip ;
$command .= $line;
$command = str_replace('prefix_', $CFG->prefix, $command); // Table prefixes
if (! execute_sql($command)) {
$success = false;
}
$command = '';
} else {
$command .= $line;
}
}
}
return $success;
}
/// GENERIC FUNCTIONS TO CHECK AND COUNT RECORDS ////////////////////////////////////////
/**
* Test whether a record exists in a table where all the given fields match the given values.
*
* The record to test is specified by giving up to three fields that must
* equal the corresponding values.
*
* @uses $CFG
* @param string $table The table to check.
* @param string $field1 the first field to check (optional).
* @param string $value1 the value field1 must have (requred if field1 is given, else optional).
* @param string $field2 the second field to check (optional).
* @param string $value2 the value field2 must have (requred if field2 is given, else optional).
* @param string $field3 the third field to check (optional).
* @param string $value3 the value field3 must have (requred if field3 is given, else optional).
* @return bool true if a matching record exists, else false.
*/
function record_exists($table, $field1='', $value1='', $field2='', $value2='', $field3='', $value3='') {
global $CFG;
$select = where_clause($field1, $value1, $field2, $value2, $field3, $value3);
return record_exists_sql('SELECT * FROM '. $CFG->prefix . $table .' '. $select);
}
/**
* Test whether any records exists in a table which match a particular WHERE clause.
*
* @uses $CFG
* @param string $table The database table to be checked against.
* @param string $select A fragment of SQL to be used in a WHERE clause in the SQL call.
* @return bool true if a matching record exists, else false.
*/
function record_exists_select($table, $select='') {
global $CFG;
if ($select) {
$select = 'WHERE '.$select;
}
return record_exists_sql('SELECT * FROM '. $CFG->prefix . $table . ' ' . $select);
}
/**
* 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 $sql The SQL statement to execute.
* @return bool true if the SQL executes without errors and returns at least one record.
*/
function record_exists_sql($sql) {
$limitfrom = 0; /// Number of records to skip
$limitnum = 1; /// Number of records to retrieve
$rs = get_recordset_sql($sql, $limitfrom, $limitnum);
if ($rs && $rs->RecordCount() > 0) {
return true;
} else {
return false;
}
}
/**
* Count the records in a table where all the given fields match the given values.
*
* @uses $CFG
* @param string $table The table to query.
* @param string $field1 the first field to check (optional).
* @param string $value1 the value field1 must have (requred if field1 is given, else optional).
* @param string $field2 the second field to check (optional).
* @param string $value2 the value field2 must have (requred if field2 is given, else optional).
* @param string $field3 the third field to check (optional).
* @param string $value3 the value field3 must have (requred if field3 is given, else optional).
* @return int The count of records returned from the specified criteria.
*/
function count_records($table, $field1='', $value1='', $field2='', $value2='', $field3='', $value3='') {
global $CFG;
$select = where_clause($field1, $value1, $field2, $value2, $field3, $value3);
return count_records_sql('SELECT COUNT(*) FROM '. $CFG->prefix . $table .' '. $select);
}
/**
* Count the records in a table which match a particular WHERE clause.
*
* @uses $CFG
* @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 string $countitem The count string to be used in the SQL call. Default is COUNT(*).
* @return int The count of records returned from the specified criteria.
*/
function count_records_select($table, $select='', $countitem='COUNT(*)') {
global $CFG;
if ($select) {
$select = 'WHERE '.$select;
}
return count_records_sql('SELECT '. $countitem .' FROM '. $CFG->prefix . $table .' '. $select);
}
/**
* 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 occurrs, 0 is returned.
*
* @uses $CFG
* @uses $db
* @param string $sql The SQL string you wish to be executed.
* @return int the count. If an error occurrs, 0 is returned.
*/
function count_records_sql($sql) {
$rs = get_recordset_sql($sql);
if ($rs) {
return $rs->fields[0];
} else {
return 0;
}
}
/// GENERIC FUNCTIONS TO GET, INSERT, OR UPDATE DATA ///////////////////////////////////
/**
* Get a single record as an object
*
* @uses $CFG
* @param string $table The table to select from.
* @param string $field1 the first field to check (optional).
* @param string $value1 the value field1 must have (requred if field1 is given, else optional).
* @param string $field2 the second field to check (optional).
* @param string $value2 the value field2 must have (requred if field2 is given, else optional).
* @param string $field3 the third field to check (optional).
* @param string $value3 the value field3 must have (requred if field3 is given, else optional).
* @return mixed a fieldset object containing the first mathcing record, or false if none found.
*/
function get_record($table, $field1, $value1, $field2='', $value2='', $field3='', $value3='', $fields='*') {
global $CFG;
$select = where_clause($field1, $value1, $field2, $value2, $field3, $value3);
return get_record_sql('SELECT '.$fields.' FROM '. $CFG->prefix . $table .' '. $select);
}
/**
* Get a single record as an object using an SQL statement
*
* The SQL statement should normally only return one record. In debug mode
* you will get a warning if more record is returned (unless you
* set $expectmultiple to true). In non-debug mode, it just returns
* the first record.
*
* @uses $CFG
* @uses $db
* @param string $sql The SQL string you wish to be executed, should normally only return one record.
* @param bool $expectmultiple If the SQL cannot be written to conviniently return just one record,
* set this to true to hide the debug message.
* @param bool $nolimit sometimes appending ' LIMIT 1' to the SQL causes an error. Set this to true
* to stop your SQL being modified. This argument should probably be deprecated.
* @return Found record as object. False if not found or error
*/
function get_record_sql($sql, $expectmultiple=false, $nolimit=false) {
global $CFG;
/// Default situation
$limitfrom = 0; /// Number of records to skip
$limitnum = 1; /// Number of records to retrieve
/// Only a few uses of the 2nd and 3rd parameter have been found
/// I think that we should avoid to use them completely, one
/// record is one record, and everything else should return error.
/// So the proposal is to change all the uses, (4-5 inside Moodle
/// Core), drop them from the definition and delete the next two
/// "if" sentences. (eloy, 2006-08-19)
if ($nolimit) {
$limitfrom = 0;
$limitnum = 0;
} else if ($expectmultiple) {
$limitfrom = 0;
$limitnum = 1;
} else if (isset($CFG->debug) && $CFG->debug > 7) {
// Debugging mode - don't use a limit of 1, but do change the SQL, because sometimes that
// causes errors, and in non-debug mode you don't see the error message and it is
// impossible to know what's wrong.
$limitfrom = 0;
$limitnum = 100;
}
if (!$rs = get_recordset_sql($sql, $limitfrom, $limitnum)) {
return false;
}
$recordcount = $rs->RecordCount();
if ($recordcount == 0) { // Found no records
return false;
} else if ($recordcount == 1) { // Found one record
/// DIRTY HACK to retrieve all the ' ' (1 space) fields converted back
/// to '' (empty string) for Oracle. It's the only way to work with
/// all those NOT NULL DEFAULT '' fields until we definetively delete them
if ($CFG->dbtype == 'oci8po') {
array_walk($rs->fields, 'onespace2empty');
}
/// End od DIRTY HACK
return (object)$rs->fields;
} else { // Error: found more than one record
notify('Error: Turn off debugging to hide this error.');
notify($sql . '(with limits ' . $limitfrom . ', ' . $limitnum . ')');
if ($records = $rs->GetAssoc(true)) {
notify('Found more than one record in get_record_sql !');
print_object($records);
} else {
notify('Very strange error in get_record_sql !');
print_object($rs);
}
print_continue("$CFG->wwwroot/$CFG->admin/config.php");
}
}
/**
* Gets one record from a table, as an object
*
* @uses $CFG
* @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 string $fields A comma separated list of fields to be returned from the chosen table.
* @return object|false Returns an array of found records (as objects) or false if no records or error occured.
*/
function get_record_select($table, $select='', $fields='*') {
global $CFG;
if ($select) {
$select = 'WHERE '. $select;
}
return get_record_sql('SELECT '. $fields .' FROM '. $CFG->prefix . $table .' '. $select);
}
/**
* Get a number of records as an ADODB RecordSet.
*
* Selects records from the table $table.
*
* If specified, only records where the field $field has value $value are retured.
*
* 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
* mightbe "time ASC" or "time DESC".
*
* If $fields is specified, only those fields are returned.
*
* This function is internal to datalib, and should NEVER should be called directly
* from general Moodle scripts. Use get_record, get_records etc.
*
* 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 an ADODB RecordSet object
* @link http://phplens.com/adodb/reference.functions.adorecordset.html
* if the query succeeds. If an error occurrs, false is returned.
*
* @param string $table the table to query.
* @param string $field a field to check (optional).
* @param string $value the value the field must have (requred if field1 is given, else optional).
* @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 $limitfrom is set).
* @return mixed an ADODB RecordSet object, or false if an error occured.
*/
function get_recordset($table, $field='', $value='', $sort='', $fields='*', $limitfrom='', $limitnum='') {
if ($field) {
$select = "$field = '$value'";
} else {
$select = '';
}
return get_recordset_select($table, $select, $sort, $fields, $limitfrom, $limitnum);
}
/**
* Get a number of records as an ADODB RecordSet.
*
* 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.
*
* @uses $CFG
* @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 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 $limitfrom is set).
* @return mixed an ADODB RecordSet object, or false if an error occured.
*/
function get_recordset_select($table, $select='', $sort='', $fields='*', $limitfrom='', $limitnum='') {
global $CFG;
if ($select) {
$select = ' WHERE '. $select;
}
if ($limitfrom !== '') {
$limit = sql_paging_limit($limitfrom, $limitnum);
} else {
$limit = '';
}
if ($sort) {
$sort = ' ORDER BY '. $sort;
}
return get_recordset_sql('SELECT '. $fields .' FROM '. $CFG->prefix . $table . $select . $sort .' '. $limit);
}
/**
* Get a number of records as an ADODB RecordSet.
*
* Only records where $field takes one of the values $values are returned.
* $values should be a comma-separated list of values, for example "4,5,6,10"
* or "'foo','bar','baz'".
*
* 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 string $values comma separated list of values the field must have (requred if field is given, else optional).
* @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 $limitfrom is set).
* @return mixed an ADODB RecordSet object, or false if an error occured.
*/
function get_recordset_list($table, $field='', $values='', $sort='', $fields='*', $limitfrom='', $limitnum='') {
if ($field) {
$select = "$field IN ($values)";
} else {
$select = '';
}
return get_recordset_select($table, $select, $sort, $fields, $limitfrom, $limitnum);
}
/**
* Get a number of records as an ADODB RecordSet. $sql must be a complete SQL query.
* This function is internal to datalib, and should NEVER should be called directly
* from general Moodle scripts. Use get_record, get_records etc.
*
* The return type is as for @see function get_recordset.
*
* @uses $CFG
* @uses $db
* @param string $sql the SQL select query to execute.
* @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 $limitfrom is set).
* @return mixed an ADODB RecordSet object, or false if an error occured.
*/
function get_recordset_sql($sql, $limitfrom=null, $limitnum=null) {
global $CFG, $db;
if (defined('MDL_PERFDB')) { global $PERF ; $PERF->dbqueries++; };
if ($limitfrom || $limitnum) {
///Special case, 0 must be -1 for ADOdb
$limitfrom = empty($limitfrom) ? -1 : $limitfrom;
$limitnum = empty($limitnum) ? -1 : $limitnum;
$rs = $db->SelectLimit($sql, $limitnum, $limitfrom);
} else {
$rs = $db->Execute($sql);
}
if (!$rs) {
if (isset($CFG->debug) and $CFG->debug > 7) {
notify($db->ErrorMsg() .'<br /><br />'. $sql);
}
if (!empty($CFG->dblogerror)) {
$debug=array_shift(debug_backtrace());
error_log("SQL ".$db->ErrorMsg()." in {$debug['file']} on line {$debug['line']}. STATEMENT: $sql with limits ($limitfrom, $limitnum)");
}
return false;
}
return $rs;
}
/**
* Utility function used by the following 4 methods.
*
* @param object an ADODB RecordSet object.
* @return mixed mixed an array of objects, or false if an error occured or the RecordSet was empty.
*/
function recordset_to_array($rs) {
global $CFG;
if ($rs && $rs->RecordCount() > 0) {
/// First of all, we are going to get the name of the first column
/// to introduce it back after transforming the recordset to assoc array
/// See http://docs.moodle.org/en/XMLDB_Problems, fetch mode problem.
$firstcolumn = $rs->FetchField(0);
/// Get the whole associative array
if ($records = $rs->GetAssoc(true)) {
foreach ($records as $key => $record) {
/// Really DIRTY HACK for Oracle, but it's the only way to make it work
/// until we got all those NOT NULL DEFAULT '' out from Moodle
if ($CFG->dbtype == 'oci8po') {
array_walk($record, 'onespace2empty');
}
/// End of DIRTY HACK
$record[$firstcolumn->name] = $key;/// Re-add the assoc field
$objects[$key] = (object) $record; /// To object
}
return $objects;
} else {
return false;
}
} else {
return false;
}
}
/**
* This function is used to convert all the Oracle 1-space defaults to the empty string
* like a really DIRTY HACK to allow it to work better until all those NOT NULL DEFAULT ''
* fields will be out from Moodle.
* @param string the string to be converted to '' (empty string) if it's ' ' (one space)
*/
function onespace2empty(&$item, $key) {
$item = $item == ' ' ? '' : $item;
return true;
}
/**
* Get a number of records as an array of objects.
*
* 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 string $field a field to check (optional).
* @param string $value the value the field must have (requred if field1 is given, else optional).
* @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 $limitfrom is set).
* @return mixed an array of objects, or false if no records were found or an error occured.
*/
function get_records($table, $field='', $value='', $sort='', $fields='*', $limitfrom='', $limitnum='') {
$rs = get_recordset($table, $field, $value, $sort, $fields, $limitfrom, $limitnum);
return recordset_to_array($rs);
}
/**
* Get a number of records as an array of objects.
*
* 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 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 $limitfrom is set).
* @return mixed an array of objects, or false if no records were found or an error occured.
*/
function get_records_select($table, $select='', $sort='', $fields='*', $limitfrom='', $limitnum='') {
$rs = get_recordset_select($table, $select, $sort, $fields, $limitfrom, $limitnum);
return recordset_to_array($rs);
}
/**
* Get a number of records as an array of objects.
*
* 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 Comma separated list of possible value
* @param string $sort Sort order (as valid SQL sort parameter)
* @param string $fields A comma separated list of fields to be returned from the chosen table.
* @return mixed an array of objects, or false if no records were found or an error occured.
*/
function get_records_list($table, $field='', $values='', $sort='', $fields='*', $limitfrom='', $limitnum='') {
$rs = get_recordset_list($table, $field, $values, $sort, $fields, $limitfrom, $limitnum);
return recordset_to_array($rs);
}
/**
* Get a number of records as an array of objects.
*
* Return value as for @see function get_records.
*
* @param string $sql the SQL select query to execute.
* @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 $limitfrom is set).
* @return mixed an array of objects, or false if no records were found or an error occured.
*/
function get_records_sql($sql, $limitfrom='', $limitnum='') {
$rs = get_recordset_sql($sql, $limitfrom='', $limitnum='');
return recordset_to_array($rs);
}
/**
* Utility function used by the following 3 methods.
*
* @param object an ADODB RecordSet object with two columns.
* @return mixed an associative array, or false if an error occured or the RecordSet was empty.
*/
function recordset_to_menu($rs) {
if ($rs && $rs->RecordCount() > 0) {
while (!$rs->EOF) {
$menu[$rs->fields[0]] = $rs->fields[1];
$rs->MoveNext();
}
return $menu;
} else {
return false;
}
}
/**
* Get the first two columns from a number of records as an associative array.
*
* Arguments as for @see function get_recordset.
*
* If no errors occur, and at least one records is found, the return value
* is an associative whose keys come from the first field of each record,
* and whose values are the corresponding second fields. If no records are found,
* or an error occurs, false is returned.
*
* @param string $table the table to query.
* @param string $field a field to check (optional).
* @param string $value the value the field must have (requred if field1 is given, else optional).
* @param string $sort an order to sort the results in (optional, a valid SQL ORDER BY parameter).
* @param string $fields a comma separated list of fields to return (optional, by default all fields are returned).
* @return mixed an associative array, or false if no records were found or an error occured.
*/
function get_records_menu($table, $field='', $value='', $sort='', $fields='*') {
$rs = get_recordset($table, $field, $value, $sort, $fields);
return recordset_to_menu($rs);
}
/**
* Get the first two columns from a number of records as an associative array.
*
* 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 string $sort Sort order (optional) - a valid SQL order parameter
* @param string $fields A comma separated list of fields to be returned from the chosen table.
* @return mixed an associative array, or false if no records were found or an error occured.
*/
function get_records_select_menu($table, $select='', $sort='', $fields='*') {
$rs = get_recordset_select($table, $select, $sort, $fields);
return recordset_to_menu($rs);
}
/**
* Get the first two columns from a number of records as an associative array.
*
* Arguments as for @see function get_recordset_sql.
* Return value as for @see function get_records_menu.
*
* @param string $sql The SQL string you wish to be executed.
* @return mixed an associative array, or false if no records were found or an error occured.
*/
function get_records_sql_menu($sql) {
$rs = get_recordset_sql($sql);
return recordset_to_menu($rs);
}
/**
* Get a single value from a table row where all the given fields match the given values.
*
* @param string $table the table to query.
* @param string $return the field to return the value of.
* @param string $field1 the first field to check (optional).
* @param string $value1 the value field1 must have (requred if field1 is given, else optional).
* @param string $field2 the second field to check (optional).
* @param string $value2 the value field2 must have (requred if field2 is given, else optional).
* @param string $field3 the third field to check (optional).
* @param string $value3 the value field3 must have (requred if field3 is given, else optional).
* @return mixed the specified value, or false if an error occured.
*/
function get_field($table, $return, $field1, $value1, $field2='', $value2='', $field3='', $value3='') {
global $CFG;
$select = where_clause($field1, $value1, $field2, $value2, $field3, $value3);
return get_field_sql('SELECT ' . $return . ' FROM ' . $CFG->prefix . $table . ' ' . $select);
}
/**
* Get a single value from a table row where a particular select clause is true.
*
* @uses $CFG
* @param string $table the table to query.
* @param string $return the field to return the value of.
* @param string $select A fragment of SQL to be used in a where clause in the SQL call.
* @return mixed the specified value, or false if an error occured.
*/
function get_field_select($table, $return, $select) {
global $CFG;
if ($select) {
$select = 'WHERE '. $select;
}
return get_field_sql('SELECT ' . $return . ' FROM ' . $CFG->prefix . $table . ' ' . $select);
}
/**
* Get a single value from a table.
*
* @param string $sql an SQL statement expected to return a single value.
* @return mixed the specified value, or false if an error occured.
*/
function get_field_sql($sql) {
$rs = get_recordset_sql($sql);
if ($rs && $rs->RecordCount() == 1) {
return $rs->fields[0];
} else {
return false;
}
}
/**
* Get an array of data from one or more fields from a database
* use to get a column, or a series of distinct values
*
* @uses $CFG
* @uses $db
* @param string $sql The SQL string you wish to be executed.
* @return mixed|false Returns the value return from the SQL statment or false if an error occured.
* @todo Finish documenting this function
*/
function get_fieldset_sql($sql) {
global $db, $CFG;
if (defined('MDL_PERFDB')) { global $PERF ; $PERF->dbqueries++; };
$rs = $db->Execute($sql);
if (!$rs) {
if (isset($CFG->debug) and $CFG->debug > 7) {
notify($db->ErrorMsg() .'<br /><br />'. $sql);
}
if (!empty($CFG->dblogerror)) {
$debug=array_shift(debug_backtrace());
error_log("SQL ".$db->ErrorMsg()." in {$debug['file']} on line {$debug['line']}. STATEMENT: $sql");
}
return false;
}
if ( $rs->RecordCount() > 0 ) {
$results = array();
while (!$rs->EOF) {
array_push($results, $rs->fields[0]);
$rs->MoveNext();
}
return $results;
} else {
return false;
}
}
/**
* Set a single field in every table row where all the given fields match the given values.
*
* @uses $CFG
* @uses $db
* @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 $field1 the first field to check (optional).
* @param string $value1 the value field1 must have (requred if field1 is given, else optional).
* @param string $field2 the second field to check (optional).
* @param string $value2 the value field2 must have (requred if field2 is given, else optional).
* @param string $field3 the third field to check (optional).
* @param string $value3 the value field3 must have (requred if field3 is given, else optional).
* @return mixed An ADODB RecordSet object with the results from the SQL call or false.
*/
function set_field($table, $newfield, $newvalue, $field1, $value1, $field2='', $value2='', $field3='', $value3='') {
global $db, $CFG;
if (defined('MDL_PERFDB')) { global $PERF ; $PERF->dbqueries++; };
$select = where_clause($field1, $value1, $field2, $value2, $field3, $value3);
return $db->Execute('UPDATE '. $CFG->prefix . $table .' SET '. $newfield .' = \''. $newvalue .'\' '. $select);
}
/**
* Delete the records from a table where all the given fields match the given values.
*
* @uses $CFG
* @uses $db
* @param string $table the table to delete from.
* @param string $field1 the first field to check (optional).
* @param string $value1 the value field1 must have (requred if field1 is given, else optional).
* @param string $field2 the second field to check (optional).
* @param string $value2 the value field2 must have (requred if field2 is given, else optional).
* @param string $field3 the third field to check (optional).
* @param string $value3 the value field3 must have (requred if field3 is given, else optional).
* @return mixed An ADODB RecordSet object with the results from the SQL call or false.
*/
function delete_records($table, $field1='', $value1='', $field2='', $value2='', $field3='', $value3='') {
global $db, $CFG;
if (defined('MDL_PERFDB')) { global $PERF ; $PERF->dbqueries++; };
$select = where_clause($field1, $value1, $field2, $value2, $field3, $value3);
return $db->Execute('DELETE FROM '. $CFG->prefix . $table .' '. $select);
}
/**
* Delete one or more records from a table
*
* @uses $CFG
* @uses $db
* @param string $table The database table to be checked against.
* @param string $select A fragment of SQL to be used in a where clause in the SQL call (used to define the selection criteria).
* @return object A PHP standard object with the results from the SQL call.
* @todo Verify return type.
*/
function delete_records_select($table, $select='') {
global $CFG, $db;
if (defined('MDL_PERFDB')) { global $PERF ; $PERF->dbqueries++; };
if ($select) {
$select = 'WHERE '.$select;
}
return $db->Execute('DELETE FROM '. $CFG->prefix . $table .' '. $select);
}
/**
* Insert a record into a table and return the "id" field if required
*
* If the return ID isn't required, then this just reports success as true/false.
* $dataobject is an object containing needed data
*
* @uses $db
* @uses $CFG
* @param string $table The database table to be checked against.
* @param array $dataobject 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.
* @param string $primarykey The primary key of the table we are inserting into (almost always "id")
*/
function insert_record($table, $dataobject, $returnid=true, $primarykey='id') {
global $db, $CFG, $empty_rs_cache;
/// DIRTY HACK: Implement one cache to store meta data (needed by Oracle inserts)
/// TODO: Possibly make it global to benefit other functions needing it (update_record...)
if (!isset($metadatacache)) {
$metadatacache = array();
}
/// End DIRTY HACK
if (defined('MDL_PERFDB')) { global $PERF ; $PERF->dbqueries++; };
/// In Moodle we always use auto-numbering fields for the primary key
/// so let's unset it now before it causes any trouble later
unset($dataobject->{$primarykey});
/// Get an empty recordset. Cache for multiple inserts.
if (empty($empty_rs_cache[$table])) {
/// Execute a dummy query to get an empty recordset
if (!$empty_rs_cache[$table] = $db->Execute('SELECT * FROM '. $CFG->prefix . $table .' WHERE '. $primarykey .' = \'-1\'')) {
return false;
}
}
$rs = $empty_rs_cache[$table];
/// Postgres doesn't have the concept of primary key built in
/// and will return the OID which isn't what we want.
/// The efficient and transaction-safe strategy is to
/// move the sequence forward first, and make the insert
/// with an explicit id.
if ( $CFG->dbtype === 'postgres7' && $returnid == true ) {
if ($nextval = (int)get_field_sql("SELECT NEXTVAL('{$CFG->prefix}{$table}_{$primarykey}_seq')")) {
$dataobject->{$primarykey} = $nextval;
}
}
/// First basic support of insert for Oracle. As it doesn't
/// support autogenerated fields, we rely on the corresponding
/// sequence. It will work automatically, unless we need to
/// return the primary from the function, in this case we
/// get the next sequence value here and insert it manually.
if ( $CFG->dbtype === 'oci8po' && $returnid == true) {
/// We need this here (move this function to dmlib?)
include_once($CFG->libdir . '/xmldb/classes/generators/XMLDBGenerator.class.php');
include_once($CFG->libdir . '/xmldb/classes/generators/oci8po/oci8po.class.php');
$generator = new XMLDBoci8po();
$generator->setPrefix($CFG->prefix);
$seqname = $generator->getNameForObject($table, $primarykey, 'seq');
if ($nextval = (int)get_field_sql("SELECT $seqname.NEXTVAL from dual")) {
$dataobject->{$primarykey} = $nextval;
}
}
/// Also, for Oracle DB, empty strings are converted to NULLs in DB
/// and this breaks a lot of NOT NULL columns currenty Moodle. In the future it's
/// planned to move some of them to NULL, if they must accept empty values and this
/// piece of code will become less and less used. But, for now, we need it.
/// What we are going to do is to examine all the data being inserted and if it's
/// an empty string (NULL for Oracle) and the field is defined as NOT NULL, we'll modify
/// such data in the best form possible ("0" for booleans and numbers and " " for the
/// rest of strings. It isn't optimal, but the only way to do so.
/// In the oppsite, when retrieving records from Oracle, we'll decode " " back to
/// empty strings to allow everything to work properly. DIRTY HACK.
if ( $CFG->dbtype === 'oci8po') {
/// Get Meta info to know what to change, using the cached meta if exists
if (!isset($metadatacache[$table])) {
$metadatacache[$table] = array_change_key_case($db->MetaColumns($CFG->prefix . $table), CASE_LOWER);
}
$columns = $metadatacache[$table];
/// Iterate over all the fields in the insert, transforming values
/// in the best possible form
foreach ($dataobject as $fieldname => $fieldvalue) {
/// If the field doesn't exist in metadata, skip
if (!isset($columns[strtolower($fieldname)])) {
continue;
}
/// If the field ins't VARCHAR or CLOB, skip
if ($columns[strtolower($fieldname)]->type != 'VARCHAR2' && $columns[strtolower($fieldname)]->type != 'CLOB') {
continue;
}
/// If the field isn't NOT NULL, skip (it's nullable, so accept empty values)
if (!$columns[strtolower($fieldname)]->not_null) {
continue;
}
/// If the value isn't empty, skip
if (!empty($fieldvalue)) {
continue;
}
/// Now, we have one empty value, going to be inserted to one NOT NULL, VARCHAR2 or CLOB field
/// Try to get the best value to be inserted
if (gettype($fieldvalue) == 'boolean') {
$dataobject->$fieldname = '0'; /// Transform false to '0' that evaluates the same for PHP
} else if (gettype($fieldvalue) == 'integer') {
$dataobject->$fieldname = '0'; /// Transform 0 to '0' that evaluates the same for PHP
} else if (gettype($fieldvalue) == 'NULL') {
$dataobject->$fieldname = '0'; /// Transform NULL to '0' that evaluates the same for PHP
} else {
$dataobject->$fieldname = ' '; /// Transform '' to ' ' that DONT'T EVALUATE THE SAME
/// (we'll transform back again on get_records_XXX functions)!!
}
}
}
/// End of DIRTY HACK
/// Get the correct SQL from adoDB
if (!$insertSQL = $db->GetInsertSQL($rs, (array)$dataobject, true)) {
return false;
}
/// Run the SQL statement
if (!$rs = $db->Execute($insertSQL)) {
if (isset($CFG->debug) and $CFG->debug > 7) {
notify($db->ErrorMsg() .'<br /><br />'.$insertSQL);
}
if (!empty($CFG->dblogerror)) {
$debug=array_shift(debug_backtrace());
error_log("SQL ".$db->ErrorMsg()." in {$debug['file']} on line {$debug['line']}. STATEMENT: $insertSQL");
}
return false;
}
/// If a return ID is not needed then just return true now
if (!$returnid) {
return true;
}
/// We already know the record PK if it's been passed explicitly,
/// or if we've retrieved it from a sequence (Postgres).
if (!empty($dataobject->{$primarykey})) {
return $dataobject->{$primarykey};
}
/// This only gets triggered with non-Postgres databases
/// however we have some postgres fallback in case we failed
/// to find the sequence.
$id = $db->Insert_ID();
if ($CFG->dbtype === 'postgres7') {
// try to get the primary key based on id
if ( ($rs = $db->Execute('SELECT '. $primarykey .' FROM '. $CFG->prefix . $table .' WHERE oid = '. $id))
&& ($rs->RecordCount() == 1) ) {
trigger_error("Retrieved $primarykey from oid on table $table because we could not find the sequence.");
return (integer)$rs->fields[0];
}
trigger_error('Failed to retrieve primary key after insert: SELECT '. $primarykey .
' FROM '. $CFG->prefix . $table .' WHERE oid = '. $id);
return false;
}
return (integer)$id;
}
/**
* 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
*
* @uses $CFG
* @uses $db
* @param string $table The database table to be checked against.
* @param array $dataobject An object with contents equal to fieldname=>fieldvalue. Must have an entry for 'id' to map to the table specified.
* @return bool
*/
function update_record($table, $dataobject) {
global $db, $CFG;
if (! isset($dataobject->id) ) {
return false;
}
// Determine all the fields in the table
if (!$columns = $db->MetaColumns($CFG->prefix . $table)) {
return false;
}
$data = (array)$dataobject;
if (defined('MDL_PERFDB')) { global $PERF ; $PERF->dbqueries++; };
// Pull out data matching these fields
foreach ($columns as $column) {
if ($column->name <> 'id' and isset($data[$column->name]) ) {
$ddd[$column->name] = $data[$column->name];
// PostgreSQL bytea support
if ($CFG->dbtype == 'postgres7' && $column->type == 'bytea') {
$ddd[$column->name] = $db->BlobEncode($ddd[$column->name]);
}
}
}
// Construct SQL queries
$numddd = count($ddd);
$count = 0;
$update = '';
foreach ($ddd as $key => $value) {
$count++;
$update .= $key .' = \''. $value .'\''; // All incoming data is already quoted
if ($count < $numddd) {
$update .= ', ';
}
}
if ($rs = $db->Execute('UPDATE '. $CFG->prefix . $table .' SET '. $update .' WHERE id = \''. $dataobject->id .'\'')) {
return true;
} else {
if (isset($CFG->debug) and $CFG->debug > 7) {
notify($db->ErrorMsg() .'<br /><br />UPDATE '. $CFG->prefix . $table .' SET '. $update .' WHERE id = \''. $dataobject->id .'\'');
}
if (!empty($CFG->dblogerror)) {
$debug=array_shift(debug_backtrace());
error_log("SQL ".$db->ErrorMsg()." in {$debug['file']} on line {$debug['line']}. STATEMENT: UPDATE $CFG->prefix$table SET $update WHERE id = '$dataobject->id'");
}
return false;
}
}
/**
* Returns the proper SQL to do paging
*
* @uses $CFG
* @param string $page Offset page number
* @param string $recordsperpage Number of records per page
* @deprecated Moodle 1.7 use the new $limitfrom, $limitnum available in all
* the get_recordXXX() funcions.
* @return string
*/
function sql_paging_limit($page, $recordsperpage) {
global $CFG;
switch ($CFG->dbtype) {
case 'postgres7':
return 'LIMIT '. $recordsperpage .' OFFSET '. $page;
default:
return 'LIMIT '. $page .','. $recordsperpage;
}
}
/**
* Returns the proper SQL to do LIKE in a case-insensitive way
*
* @uses $CFG
* @return string
*/
function sql_ilike() {
global $CFG;
switch ($CFG->dbtype) {
case 'mysql':
return 'LIKE';
default:
return 'ILIKE';
}
}
/**
* Returns the proper SQL to do LIKE in a case-insensitive way
*
* @uses $CFG
* @param string $firstname User's first name
* @param string $lastname User's last name
* @return string
*/
function sql_fullname($firstname='firstname', $lastname='lastname') {
global $CFG;
switch ($CFG->dbtype) {
case 'mysql':
return ' CONCAT('. $firstname .'," ",'. $lastname .') ';
case 'postgres7':
return " ". $firstname ."||' '||". $lastname ." ";
case 'mssql':
return " ". $firstname ."+' '+". $lastname ." ";
default:
return ' '. $firstname .'||" "||'. $lastname .' ';
}
}
/**
* Returns the proper SQL to do IS NULL
* @uses $CFG
* @param string $fieldname The field to add IS NULL to
* @return string
*/
function sql_isnull($fieldname) {
global $CFG;
switch ($CFG->dbtype) {
case 'mysql':
return $fieldname.' IS NULL';
default:
return $fieldname.' IS NULL';
}
}
/**
* Returns the proper AS keyword to be used to aliase columns
* SQL defines the keyword as optional and nobody but PG
* seems to require it. This function should be used inside all
* the statements using column aliases.
* Note than the use of table aliases doesn't require the
* AS keyword at all, only columns for postgres.
* @uses $CFG
* @ return string the keyword
*/
function sql_as() {
global $CFG, $db;
switch ($CFG->dbtype) {
case 'postgres7':
return 'AS';
default:
return '';
}
}
/**
* 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.
*/
function sql_order_by_text($fieldname, $numchars=32) {
global $CFG;
switch ($CFG->dbtype) {
case 'mssql':
return 'CONVERT(varchar, ' . $fieldname . ', ' . $numchars . ')';
break;
case 'oci8po':
return 'dbms_lob.substr(' . $fieldname . ', ' . $numchars . ',1)';
break;
default:
return $fieldname;
}
}
/**
* Prepare a SQL WHERE clause to select records where the given fields match the given values.
*
* Prepares a where clause of the form
* WHERE field1 = value1 AND field2 = value2 AND field3 = value3
* except that you need only specify as many arguments (zero to three) as you need.
*
* @param string $field1 the first field to check (optional).
* @param string $value1 the value field1 must have (requred if field1 is given, else optional).
* @param string $field2 the second field to check (optional).
* @param string $value2 the value field2 must have (requred if field2 is given, else optional).
* @param string $field3 the third field to check (optional).
* @param string $value3 the value field3 must have (requred if field3 is given, else optional).
*/
function where_clause($field1='', $value1='', $field2='', $value2='', $field3='', $value3='') {
if ($field1) {
$select = "WHERE $field1 = '$value1'";
if ($field2) {
$select .= " AND $field2 = '$value2'";
if ($field3) {
$select .= " AND $field3 = '$value3'";
}
}
} else {
$select = '';
}
return $select;
}
/**
* Get the data type of a table column, using an ADOdb MetaType() call.
*
* @uses $CFG
* @uses $db
* @param string $table The name of the database table
* @param string $column The name of the field in the table
* @return string Field type or false if error
*/
function column_type($table, $column) {
global $CFG, $db;
if (defined('MDL_PERFDB')) { global $PERF ; $PERF->dbqueries++; };
if(!$rs = $db->Execute('SELECT '.$column.' FROM '.$CFG->prefix.$table.' LIMIT 0')) {
return false;
}
$field = $rs->FetchField(0);
return $rs->MetaType($field->type);
}
/**
* This function will execute an array of SQL commands, returning
* true/false if any error is found and stopping/continue as desired.
* It's widely used by all the ddllib.php functions
*
* @param array sqlarr array of sql statements to execute
* @param boolean continue to specify if must continue on error (true) or stop (false)
* @param boolean feedback to specify to show status info (true) or not (false)
* @param boolean true if everything was ok, false if some error was found
*/
function execute_sql_arr($sqlarr, $continue=true, $feedback=true) {
if (!is_array($sqlarr)) {
return false;
}
$status = true;
foreach($sqlarr as $sql) {
if (!execute_sql($sql, $feedback)) {
$status = false;
if (!$continue) {
break;
}
}
}
return $status;
}
/**
* This function, called from setup.php includes all the configuration
* needed to properly work agains any DB. It setups connection encoding
* and some other variables.
*/
function configure_dbconnection() {
global $CFG, $db;
switch ($CFG->dbtype) {
case 'mysql':
/// Set names if needed
if ($CFG->unicodedb) {
$db->Execute("SET NAMES 'utf8'");
}
break;
case 'postgres7':
/// Set names if needed
if ($CFG->unicodedb) {
$db->Execute("SET NAMES 'utf8'");
}
break;
case 'mssql':
/// No need to set charset. It must be specified in the driver conf
/// Allow quoted identifiers
$db->Execute('SET QUOTED_IDENTIFIER ON');
/// Enable sybase quotes, so addslashes and stripslashes will use "'"
ini_set('magic_quotes_sybase', '1');
/// NOTE: Not 100% useful because GPC has been addslashed with the setting off
/// so IT'S MANDATORY TO CHANGE THIS UNDER php.ini or .htaccess for this DB
break;
case 'oci8po':
/// No need to set charset. It must be specified by the NLS_LANG env. variable
/// Enable sybase quotes, so addslashes and stripslashes will use "'"
ini_set('magic_quotes_sybase', '1');
/// NOTE: Not 100% useful because GPC has been addslashed with the setting off
/// so IT'S MANDATORY TO ENABLE THIS UNDER php.ini or .htaccess for this DB
break;
}
}
?>
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