mysql.class.php

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<?php // $Id: mysql.class.php,v 1.38.2.2 2009/03/02 18:53:16 stronk7 Exp $

///////////////////////////////////////////////////////////////////////////
//                                                                       //
// NOTICE OF COPYRIGHT                                                   //
//                                                                       //
// Moodle - Modular Object-Oriented Dynamic Learning Environment         //
//          http://moodle.com                                            //
//                                                                       //
// Copyright (C) 1999 onwards 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 generate SQL code to be used against MySQL
/// It extends XMLDBgenerator so everything can be
/// overriden as needed to generate correct SQL.

class XMLDBmysql extends XMLDBGenerator {

/// Only set values that are different from the defaults present in XMLDBgenerator

    var $quote_string = '`';   // String used to quote names

    var $default_for_char = '';      // To define the default to set for NOT NULLs CHARs without default (null=do nothing)

    var $drop_default_clause_required = true; //To specify if the generator must use some DEFAULT clause to drop defaults
    var $drop_default_clause = 'NULL'; //The DEFAULT clause required to drop defaults

    var $primary_key_name = ''; //To force primary key names to one string (null=no force)

    var $drop_primary_key = 'ALTER TABLE TABLENAME DROP PRIMARY KEY'; // Template to drop PKs
                // with automatic replace for TABLENAME and KEYNAME

    var $drop_unique_key = 'ALTER TABLE TABLENAME DROP KEY KEYNAME'; // Template to drop UKs
                // with automatic replace for TABLENAME and KEYNAME

    var $drop_foreign_key = 'ALTER TABLE TABLENAME DROP FOREIGN KEY KEYNAME'; // Template to drop FKs
                // with automatic replace for TABLENAME and KEYNAME

    var $sequence_extra_code = false; //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 $enum_extra_code = false; //Does the generator need to add extra code to generate code for the enums in the table

    var $add_after_clause = true; // Does the generator need to add the after clause for fields

    var $concat_character = null; //Characters to be used as concatenation operator. If not defined
                                  //MySQL CONCAT function will be use

    var $alter_column_sql = 'ALTER TABLE TABLENAME MODIFY COLUMN COLUMNSPECS'; //The SQL template to alter columns

    var $drop_index_sql = 'ALTER TABLE TABLENAME DROP INDEX INDEXNAME'; //SQL sentence to drop one index
                                                               //TABLENAME, INDEXNAME are dinamically replaced

    var $rename_index_sql = null; //SQL sentence to rename one index (MySQL doesn't support this!)
                                      //TABLENAME, OLDINDEXNAME, NEWINDEXNAME are dinamically replaced

    var $rename_key_sql = null; //SQL sentence to rename one key (MySQL doesn't support this!)
                                      //TABLENAME, OLDKEYNAME, NEWKEYNAME are dinamically replaced

    /**
     * Creates one new XMLDBmysql
     */
    function XMLDBmysql() {
        parent::XMLDBGenerator();
        global $CFG;
        $this->prefix = '';
        $this->reserved_words = $this->getReservedWords();
    }

    /**
     * Given one XMLDB Type, lenght and decimals, returns the DB proper SQL type
     */
    function getTypeSQL ($xmldb_type, $xmldb_length=null, $xmldb_decimals=null) {

        switch ($xmldb_type) {
            case XMLDB_TYPE_INTEGER:    // From http://mysql.com/doc/refman/5.0/en/numeric-types.html!
                if (empty($xmldb_length)) {
                    $xmldb_length = 10;
                }
                if ($xmldb_length > 9) {
                    $dbtype = 'BIGINT';
                } else if ($xmldb_length > 6) {
                    $dbtype = 'INT';
                } else if ($xmldb_length > 4) {
                    $dbtype = 'MEDIUMINT';
                } else if ($xmldb_length > 2) {
                    $dbtype = 'SMALLINT';
                } else {
                    $dbtype = 'TINYINT';
                }
                $dbtype .= '(' . $xmldb_length . ')';
                break;
            case XMLDB_TYPE_NUMBER:
                $dbtype = $this->number_type;
                if (!empty($xmldb_length)) {
                    $dbtype .= '(' . $xmldb_length;
                    if (!empty($xmldb_decimals)) {
                        $dbtype .= ',' . $xmldb_decimals;
                    }
                    $dbtype .= ')';
                }
                break;
            case XMLDB_TYPE_FLOAT:
                $dbtype = 'DOUBLE';
                if (!empty($xmldb_decimals)) {
                    if ($xmldb_decimals < 6) {
                        $dbtype = 'FLOAT';
                    }
                }
                if (!empty($xmldb_length)) {
                    $dbtype .= '(' . $xmldb_length;
                    if (!empty($xmldb_decimals)) {
                        $dbtype .= ',' . $xmldb_decimals;
                    }
                    $dbtype .= ')';
                }
                break;
            case XMLDB_TYPE_CHAR:
                $dbtype = 'VARCHAR';
                if (empty($xmldb_length)) {
                    $xmldb_length='255';
                }
                $dbtype .= '(' . $xmldb_length . ')';
                break;
            case XMLDB_TYPE_TEXT:
                if (empty($xmldb_length)) {
                    $xmldb_length = 'small';
                }
                if ($xmldb_length == 'small') {
                    $dbtype = 'TEXT';
                } else if ($xmldb_length == 'medium') {
                    $dbtype = 'MEDIUMTEXT';
                } else {
                    $dbtype = 'LONGTEXT';
                }
                break;
            case XMLDB_TYPE_BINARY:
                if (empty($xmldb_length)) {
                    $xmldb_length = 'small';
                }
                if ($xmldb_length == 'small') {
                    $dbtype = 'BLOB';
                } else if ($xmldb_length == 'medium') {
                    $dbtype = 'MEDIUMBLOB';
                } else {
                    $dbtype = 'LONGBLOB';
                }
                break;
            case XMLDB_TYPE_DATETIME:
                $dbtype = 'DATETIME';
        }
        return $dbtype;
    }

    /**
     * Given one XMLDBTable and one XMLDBField, return the SQL statements needded to create its enum 
     * (usually invoked from getModifyEnumSQL()
     */
    function getCreateEnumSQL($xmldb_table, $xmldb_field) {
    /// For MySQL, just alter the field
        return $this->getAlterFieldSQL($xmldb_table, $xmldb_field);
    }

    /**     
     * Given one XMLDBTable and one XMLDBField, return the SQL statements needded to drop its enum 
     * (usually invoked from getModifyEnumSQL()
     */
    function getDropEnumSQL($xmldb_table, $xmldb_field) {
    /// For MySQL, just alter the field
        return $this->getAlterFieldSQL($xmldb_table, $xmldb_field);
    }

    /**
     * Given one XMLDBTable and one XMLDBField, return the SQL statements needded to create its default 
     * (usually invoked from getModifyDefaultSQL()
     */
    function getCreateDefaultSQL($xmldb_table, $xmldb_field) {
    /// Just a wrapper over the getAlterFieldSQL() function for MySQL that
    /// is capable of handling defaults
        return $this->getAlterFieldSQL($xmldb_table, $xmldb_field);