Initial commit of the base generator class.

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stronk7 2006-08-16 17:28:41 +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 //
// (C) 2001-3001 Eloy Lafuente (stronk7) http://contiento.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 class represent the base generator class where all the
/// needed functions to generate proper SQL are defined.
/// If fact, this class generate SQL code to be used against MySQL
/// so the rest of classes will inherit, by default, the same logic.
/// Functions will be overriden as needed to generate correct SQL.
class XMLDBgenerator {
/// Please, avoid editing this defaults in this base class!
/// It could change the behaviour of the rest of generators
/// that, by default, inherit this configuration.
/// To change any of them, do it in extended classes instead.
var $quote_string = '"'; // String used to quote names
var $quote_all = false; // To decide if we want to quote all the names or only the reserved ones
var $integer_to_number = false; // To create all the integers as NUMBER(x) (also called DECIMAL, NUMERIC...)
var $float_to_number = false; // To create all the floats as NUMBER(x) (also called DECIMAL, NUMERIC...)
var $number_type = 'NUMERIC'; // Proper type for NUMBER(x) in this DB
var $unsigned_allowed = true; // To define in the generator must handle unsigned information
var $default_for_char = ''; // To define the default to set for NOT NULLs CHARs without default (null=do nothing)
var $primary_key_name = null; //To force primary key names to one string (null=no force)
var $primary_keys = true; // Does the generator build primary keys
var $unique_keys = true; // Does the generator build unique keys
var $foreign_keys = true; // Does the generator build foreign keys
var $primary_index = true;// Does the generator need to build one index for primary keys
var $unique_index = true; // Does the generator need to build one index for unique keys
var $foreign_index = true; // Does the generator need to build one index for foreign keys
var $sequence_extra_code = true; //Does the generator need to add extra code to generate the sequence fields
var $sequence_name = 'auto_increment'; //Particular name for inline sequences in this generator
var $sequence_only = false; //To avoid to output the rest of the field specs, leaving only the name and the sequence_name variable
var $enum_extra_code = true; //Does the generator need to add extra code to generate code for the enums in the table
var $add_table_comments = true; // Does the generator need to add code for table comments
var $prefix_on_names = true; //Does the generator need to prepend the prefix to all the key/index/sequence/trigger/check names
var $names_max_length = 30; //Max length for key/index/sequence/trigger/check names
var $prefix; // Prefix to be used for all the DB objects
var $reserved_words; // List of reserved words (in order to quote them properly)
/**
* Creates one new XMLDBGenerator
*/
function XMLDBgenerator() {
global $CFG;
$this->prefix = '';
$this->reserved_words = $this->getReservedWords();
}
/// ALL THESE FUNCTION ARE SHARED BY ALL THE XMLDGenerator classes
/**
* Set the prefix
*/
function setPrefix($prefix) {
$this->prefix = $prefix;
}
/**
* Given one correct XMLDBTable, returns the complete SQL lines to create it
*/
function getCreateTableSQL($xmldb_table) {
/// Table header
$table = 'CREATE TABLE ' . $this->getEncQuoted($this->prefix . $xmldb_table->getName()) . ' (';
if (!$xmldb_fields = $xmldb_table->getFields()) {
return false;
}
/// Add the fields, separated by commas
foreach ($xmldb_fields as $xmldb_field) {
$table .= "\n " . $this->getFieldSQL($xmldb_field) . ',';
}
/// Add the keys, separated by commas
if ($xmldb_keys = $xmldb_table->getKeys()) {
foreach ($xmldb_keys as $xmldb_key) {
if ($keytext = $this->getKeySQL($xmldb_table, $xmldb_key)) {
$table .= "\nCONSTRAINT " . $keytext . ',';
}
/// If the key is XMLDB_KEY_FOREIGN_UNIQUE, create it as UNIQUE too
if ($xmldb_key->getType() == XMLDB_KEY_FOREIGN_UNIQUE) {
///Duplicate the key
$xmldb_key->setType(XMLDB_KEY_UNIQUE);
if ($keytext = $this->getKeySQL($xmldb_table, $xmldb_key)) {
$table .= "\nCONSTRAINT " . $keytext . ',';
}
}
}
}
/// Add enum extra code if needed
if ($this->enum_extra_code) {
/// Iterate over fields looking for sequences
foreach ($xmldb_fields as $xmldb_field) {
if ($xmldb_field->getEnum()) {
$table .= "\n" . $this->getEnumExtraSQL($xmldb_table, $xmldb_field) . ',';
}
}
}
/// Table footer, trim the latest comma
$table = trim($table,',');
$table .= "\n)";
/// Add comments if specified
if ($this->add_table_comments) {
$table .= $this->getCommentSQL ($xmldb_table) . "\n";
}
/// Add the indexes (each one, one statement)
$indexcombs = array(); //To store all the key combinations used
if ($xmldb_indexes = $xmldb_table->getIndexes()) {
foreach ($xmldb_indexes as $xmldb_index) {
$fieldsarr = $xmldb_index->getFields();
sort ($fieldsarr);
$currentcomb = strtolower(implode('-', $fieldsarr));
if ($indextext = $this->getCreateIndexSQL($xmldb_table, $xmldb_index)) {
/// Only create the index if the combination hasn't been used before
if (!in_array($currentcomb, $indexcombs)) {
$table .= "\n" . $indextext;
}
}
/// Add the index to the array of used combinations
$indexcombs[] = $currentcomb;
}
}
/// Also, add the indexes needed from keys, based on configuration (each one, one statement)
if ($xmldb_keys = $xmldb_table->getKeys()) {
foreach ($xmldb_keys as $xmldb_key) {
$index = null;
switch ($xmldb_key->getType()) {
case XMLDB_KEY_PRIMARY:
if ($this->primary_index) {
$index = new XMLDBIndex('temp_index');
$index->setUnique(true);
$index->setFields($xmldb_key->getFields());
}
break;
case XMLDB_KEY_UNIQUE:
case XMLDB_KEY_FOREIGN_UNIQUE:
if ($this->unique_index) {
$index = new XMLDBIndex('temp_index');
$index->setUnique(true);
$index->setFields($xmldb_key->getFields());
}
break;
case XMLDB_KEY_FOREIGN:
if ($this->foreign_index) {
$index = new XMLDBIndex('temp_index');
$index->setUnique(false);
$index->setFields($xmldb_key->getFields());
}
break;
}
if ($index) {
if ($indextext = $this->getCreateIndexSQL($xmldb_table, $index)) {
$fieldsarr = $index->getFields();
sort ($fieldsarr);
$currentcomb = strtolower(implode('-', $fieldsarr));
/// Only create the index if the combination hasn't been used before
if (!in_array($currentcomb, $indexcombs)) {
$table .= "\n" . $indextext;
}
}
/// Add the index to the array of used combinations
$indexcombs[] = $currentcomb;
}
}
}
/// Add sequence extra code if needed
if ($this->sequence_extra_code) {
/// Iterate over fields looking for sequences
foreach ($xmldb_fields as $xmldb_field) {
if ($xmldb_field->getSequence()) {
$table .= "\n" . $this->getCreateSequenceSQL($xmldb_table, $xmldb_field);
}
}
}
return $table;
}
/**
* Given one correct XMLDBIndex, returns the complete SQL line to create it
*/
function getCreateIndexSQL ($xmldb_table, $xmldb_index) {
$unique = '';
$suffix = 'ix';
if ($xmldb_index->getUnique()) {
$unique = ' UNIQUE';
$suffix = 'uix';
}
$index = 'CREATE' . $unique . ' INDEX ';
$index .= $this->getNameForObject($xmldb_table->getName(), implode(', ', $xmldb_index->getFields()), $suffix);
$index .= ' ON ' . $this->prefix . $this->getEncQuoted($xmldb_table->getName());
$index .= ' (' . implode(', ', $this->getEncQuoted($xmldb_index->getFields())) . ');';
return $index;
}
/**
* Given one correct XMLDBField, returns the complete SQL line to create it
*/
function getFieldSQL($xmldb_field) {
/// First of all, convert integers to numbers if defined
if ($this->integer_to_number) {
if ($xmldb_field->getType() == XMLDB_TYPE_INTEGER) {
$xmldb_field->setType(XMLDB_TYPE_NUMBER);
}
}
/// Same for floats
if ($this->float_to_number) {
if ($xmldb_field->getType() == XMLDB_TYPE_FLOAT) {
$xmldb_field->setType(XMLDB_TYPE_NUMBER);
}
}
/// The name
$field = $this->getEncQuoted($xmldb_field->getName());
/// The type and length (if the field isn't enum)
if (!$xmldb_field->getEnum()) {
$field .= ' ' . $this->getTypeSQL($xmldb_field->getType(), $xmldb_field->getLength(), $xmldb_field->getDecimals());
} else {
/// call to custom function
$field .= ' ' . $this->getEnumSQL($xmldb_field);
}
/// The unsigned if supported
if ($this->unsigned_allowed && ($xmldb_field->getType() == XMLDB_TYPE_INTEGER ||
$xmldb_field->getType() == XMLDB_TYPE_NUMBER ||
$xmldb_field->getType() == XMLDB_TYPE_FLOAT)) {
if ($xmldb_field->getUnsigned()) {
$field .= ' unsigned';
}
}
/// The not null
if ($xmldb_field->getNotNull()) {
$field .= ' NOT NULL';
}
/// The sequence
if ($xmldb_field->getSequence()) {
$field .= ' ' . $this->sequence_name;
if ($this->sequence_only) {
/// We only want the field name and sequence name to be printed
/// so, calculate it and return
return $this->getEncQuoted($xmldb_field->getName()) . ' ' . $this->sequence_name;
}
}
/// The default
if ($xmldb_field->getDefault() != NULL) {
$field .= ' default ';
if ($xmldb_field->getType() == XMLDB_TYPE_CHAR ||
$xmldb_field->getType() == XMLDB_TYPE_TEXT) {
$field .= "'" . $xmldb_field->getDefault() . "'";
} else {
$field .= $xmldb_field->getDefault();
}
} else {
/// We force default '' for not null char columns without proper default
/// some day this should be out!
if ($this->default_for_char !== NULL &&
$xmldb_field->getType() == XMLDB_TYPE_CHAR &&
$xmldb_field->getNotNull()) {
$field .= ' default ' . "'" . $this->default_for_char . "'";
}
}
return $field;
}
/**
* Given one correct XMLDBKey, returns its specs
*/
function getKeySQL ($xmldb_table, $xmldb_key) {
$key = '';
switch ($xmldb_key->getType()) {
case XMLDB_KEY_PRIMARY:
if ($this->primary_keys) {
if ($this->primary_key_name !== null) {
$key = $this->primary_key_name;
} else {
$key = $this->getNameForObject($xmldb_table->getName(), implode(', ', $xmldb_key->getFields()), 'pk');
}
$key .= ' PRIMARY KEY (' . implode(', ', $this->getEncQuoted($xmldb_key->getFields())) . ')';
}
break;
case XMLDB_KEY_UNIQUE:
if ($this->unique_keys) {
$key = $this->getNameForObject($xmldb_table->getName(), implode(', ', $xmldb_key->getFields()), 'uk');
$key .= ' UNIQUE KEY (' . implode(', ', $this->getEncQuoted($xmldb_key->getFields())) . ')';
}
break;
case XMLDB_KEY_FOREIGN:
case XMLDB_KEY_FOREIGN_UNIQUE:
if ($this->foreign_keys) {
$key = $this->getNameForObject($xmldb_table->getName(), implode(', ', $xmldb_key->getFields()), 'fk');
$key .= ' FOREIGN KEY (' . implode(', ', $this->getEncQuoted($xmldb_key->getFields())) . ')';
$key .= ' REFERENCES ' . $this->getEncQuoted($xmldb_key->getRefTable());
$key .= ' (' . implode(', ', $this->getEncQuoted($xmldb_key->getRefFields())) . ')';
}
break;
}
return $key;
}
/**
* Given three strings (table name, list of fields (comma separated) and suffix), create the proper object name
*/
function getNameForObject($tablename, $fields, $suffix) {
$name = '';
/// Implement one basic cache to avoid object name duplication
if (!isset($used_names)) {
static $used_names = array();
}
/// Use standard naming. See http://docs.moodle.org/en/XMLDB_key_and_index_naming
$tablearr = explode ('_', $tablename);
foreach ($tablearr as $table) {
$name .= substr(trim($table),0,3);
}
$name .= '_';
$fieldsarr = explode (',', $fields);
foreach ($fieldsarr as $field) {
$name .= substr(trim($field),0,3);
}
/// Prepend the prefix if required
if ($this->prefix_on_names) {
$name = $this->prefix . $name;
}
$name = substr(trim($name), 0, $this->names_max_length - 1 - strlen($suffix)); //Max names_max_length
/// Add the suffix
$namewithsuffix = $name . '_' . $suffix;
/// If the calculated name is in the cache, let's modify if
if (in_array($namewithsuffix, $used_names)) {
$counter = 2;
/// If have free space, we add 2
if (strlen($namewithsuffix) < 30) {
$newname = $name . $counter;
/// Else replace the last char by 2
} else {
$newname = substr($name, 0, strlen($name)-1) . $counter;
}
$newnamewithsuffix = $newname . '_' . $suffix;
/// Now iterate until not used name is found, incrementing the counter
while (in_array($newnamewithsuffix, $used_names)) {
$newname = substr($name, 0, strlen($newname)-1) . $counter;
$newnamewithsuffix = $newname . '_' . $suffix;
$counter++;
}
$namewithsuffix = $newnamewithsuffix;
}
/// Add the name to the cache
$used_names[] = $namewithsuffix;
return $namewithsuffix;
}
/**
* Given any string (or one array), enclose it by the proper quotes
*/
function getEncQuoted($input) {
if (is_array($input)) {
foreach ($input as $key=>$content) {
$input[$key] = $this->getEncQuoted($content);
}
return $input;
} else {
/// Always lowercase
$input = strtolower($input);
/// if reserved or quote_all, quote it
if ($this->quote_all || in_array($input, $this->reserved_words)) {
$input = $this->quote_string . $input . $this->quote_string;
}
return $input;
}
}
/// ALL THESE FUNCTION MUST BE CUSTOMISED BY ALL THE XMLDGenerator classes
/**
* Given one XMLDB Type, lenght and decimals, returns the DB proper SQL type
*/
function getTypeSQL ($xmldb_type, $xmldb_length=null, $xmldb_decimals=null) {
return 'code for type(precision) goes to function getTypeSQL()';
}
/**
* Given one XMLDB Field, return its enum SQL
*/
function getEnumSQL ($xmldb_field) {
return 'code for inline enum declaration goes to function getEnumSQL()';
}
/**
* Returns the code needed to create one enum for the xmldb_table and xmldb_field passes
*/
function getEnumExtraSQL ($xmldb_table, $xmldb_field) {
return 'Code for extra enum SQL goes to getEnumExtraSQL(). Can be disabled with enum_extra_code=false';
}
/**
* Returns the code needed to create one sequence for the xmldb_table and xmldb_field passes
*/
function getCreateSequenceSQL ($xmldb_table, $xmldb_field) {
return 'Code for extra sequence SQL goes to getCreateSequenceSQL(). Can be disabled with sequence_extra_code=false';
}
/**
* Returns the code needed to add one comment to the table
*/
function getCommentSQL ($xmldb_table) {
return 'Code for table comment goes to getCommentSQL(). Can be disabled with add_table_comments=false;';
}
/**
* Returns an array of reserved words (lowercase) for this DB
* You MUST provide the real list for each DB inside every XMLDB class
*/
function getReservedWords() {
/// Some wel-know reserved words
$reserved_words = array (
'user', 'scale', 'type', 'comment'
);
return $reserved_words;
}
}
?>