moodle/lib/ddl/sqlite_sql_generator.php

306 lines
13 KiB
PHP

<?php //$Id$
///////////////////////////////////////////////////////////////////////////
// //
// 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 //
// //
///////////////////////////////////////////////////////////////////////////
require_once($CFG->libdir.'/ddl/sql_generator.php');
/// This class generate SQL code to be used against SQLite
/// It extends XMLDBgenerator so everything can be
/// overriden as needed to generate correct SQL.
class sqlite_sql_generator extends sql_generator {
/// Only set values that are different from the defaults present in XMLDBgenerator
public $drop_default_value_required = true; //To specify if the generator must use some DEFAULT clause to drop defaults
public $drop_default_value = NULL; //The DEFAULT clause required to drop defaults
public $drop_primary_key = 'ALTER TABLE TABLENAME DROP PRIMARY KEY'; // Template to drop PKs
// with automatic replace for TABLENAME and KEYNAME
public $drop_unique_key = 'ALTER TABLE TABLENAME DROP KEY KEYNAME'; // Template to drop UKs
// with automatic replace for TABLENAME and KEYNAME
public $drop_foreign_key = 'ALTER TABLE TABLENAME DROP FOREIGN KEY KEYNAME'; // Template to drop FKs
// with automatic replace for TABLENAME and KEYNAME
public $default_for_char = ''; // To define the default to set for NOT NULLs CHARs without default (null=do nothing)
public $sequence_only = true; //To avoid to output the rest of the field specs, leaving only the name and the sequence_name publiciable
public $sequence_extra_code = false; //Does the generator need to add extra code to generate the sequence fields
public $sequence_name = 'INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL'; //Particular name for inline sequences in this generator
public $unsigned_allowed = false; // To define in the generator must handle unsigned information
public $enum_extra_code = false; //Does the generator need to add extra code to generate code for the enums in the table
public $add_after_clause = true; // Does the generator need to add the after clause for fields
public $concat_character = null; //Characters to be used as concatenation operator. If not defined
//MySQL CONCAT function will be use
public $alter_column_sql = 'ALTER TABLE TABLENAME MODIFY COLUMN COLUMNSPECS'; //The SQL template to alter columns
public $drop_index_sql = 'ALTER TABLE TABLENAME DROP INDEX INDEXNAME'; //SQL sentence to drop one index
//TABLENAME, INDEXNAME are dinamically replaced
public $rename_index_sql = null; //SQL sentence to rename one index (MySQL doesn't support this!)
//TABLENAME, OLDINDEXNAME, NEWINDEXNAME are dinamically replaced
public $rename_key_sql = null; //SQL sentence to rename one key (MySQL doesn't support this!)
//TABLENAME, OLDKEYNAME, NEWKEYNAME are dinamically replaced
/**
* Creates one new XMLDBmysql
*/
public function __construct($mdb) {
parent::__construct($mdb);
}
/**
* Given one correct xmldb_key, returns its specs
*/
public function getKeySQL($xmldb_table, $xmldb_key) {
$key = '';
switch ($xmldb_key->getType()) {
case XMLDB_KEY_PRIMARY:
if ($this->primary_keys && count($xmldb_key->getFields())>1) {
if ($this->primary_key_name !== null) {
$key = $this->getEncQuoted($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 (' . 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 ' . $this->getEncQuoted($this->prefix . $xmldb_key->getRefTable());
$key .= ' (' . implode(', ', $this->getEncQuoted($xmldb_key->getRefFields())) . ')';
}
break;
}
return $key;
}
/**
* Given one XMLDB Type, lenght and decimals, returns the DB proper SQL type
*/
public function getTypeSQL($xmldb_type, $xmldb_length=null, $xmldb_decimals=null) {
switch ($xmldb_type) {
case XMLDB_TYPE_INTEGER: // From http://www.sqlite.org/datatype3.html
if (empty($xmldb_length)) {
$xmldb_length = 10;
}
$dbtype = 'INTEGER(' . $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:
$dbtype = 'REAL';
if (!empty($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_BINARY:
$dbtype = 'BLOB';
break;
case XMLDB_TYPE_DATETIME:
$dbtype = 'DATETIME';
default:
case XMLDB_TYPE_TEXT:
$dbtype = 'TEXT';
break;
}
return $dbtype;
}
/**
* Given one xmldb_table and one xmldb_field, return the SQL statements needded to create its enum
* (usually invoked from getModifyEnumSQL()
*/
public function getCreateEnumSQL($xmldb_table, $xmldb_field) {
/// For MySQL, just alter the field
return $this->getAlterFieldSQL($xmldb_table, $xmldb_field);
}
/**
* Given one xmldb_table and one xmldb_field, return the SQL statements needded to drop its enum
* (usually invoked from getModifyEnumSQL()
*/
public function getDropEnumSQL($xmldb_table, $xmldb_field) {
/// For MySQL, just alter the field
return $this->getAlterFieldSQL($xmldb_table, $xmldb_field);
}
/**
* Given one xmldb_table and one xmldb_field, return the SQL statements needded to create its default
* (usually invoked from getModifyDefaultSQL()
*/
public function getCreateDefaultSQL($xmldb_table, $xmldb_field) {
/// Just a wrapper over the getAlterFieldSQL() function for MySQL that
/// is capable of handling defaults
return $this->getAlterFieldSQL($xmldb_table, $xmldb_field);
}
/**
* Given one correct xmldb_field and the new name, returns the SQL statements
* to rename it (inside one array)
* SQLite is pretty diferent from the standard to justify this oveloading
*/
public function getRenameFieldSQL($xmldb_table, $xmldb_field, $newname) {
// TODO: Add code to rename column
/// Need a clone of xmldb_field to perform the change leaving original unmodified
$xmldb_field_clone = clone($xmldb_field);
/// Change the name of the field to perform the change
$xmldb_field_clone->setName($xmldb_field_clone->getName() . ' ' . $newname);
$fieldsql = $this->getFieldSQL($xmldb_field_clone);
$sql = 'ALTER TABLE ' . $this->getTableName($xmldb_table) . ' CHANGE ' . $fieldsql;
return array($sql);
}
/**
* Given one xmldb_table and one xmldb_field, return the SQL statements needded to drop its default
* (usually invoked from getModifyDefaultSQL()
*/
public function getDropDefaultSQL($xmldb_table, $xmldb_field) {
/// Just a wrapper over the getAlterFieldSQL() function for MySQL that
/// is capable of handling defaults
return $this->getAlterFieldSQL($xmldb_table, $xmldb_field);
}
/**
* Given one XMLDB Field, return its enum SQL
*/
public function getEnumSQL($xmldb_field) {
return 'enum';
}
/**
* Returns the code (in array) needed to add one comment to the table
*/
function getCommentSQL ($xmldb_table) {
return array();
}
/**
* Given one xmldb_table returns one array with all the check constrainsts
* in the table (fetched from DB)
* Optionally the function allows one xmldb_field to be specified in
* order to return only the check constraints belonging to one field.
* Each element contains the name of the constraint and its description
* If no check constraints are found, returns an empty array
* MySQL doesn't have check constraints in this implementation, but
* we return them based on the enum fields in the table
*/
public function getCheckConstraintsFromDB($xmldb_table, $xmldb_field = null) {
// TODO: add code for constraints
return array();
}
/**
* Given one object name and it's type (pk, uk, fk, ck, ix, uix, seq, trg)
* return if such name is currently in use (true) or no (false)
* (invoked from getNameForObject()
*/
public function isNameInUse($object_name, $type, $table_name) {
// TODO: add introspection code
return false; //No name in use found
}
/**
* Returns an array of reserved words (lowercase) for this DB
*/
public static function getReservedWords() {
/// From http://www.sqlite.org/lang_keywords.html
$reserved_words = array (
'ADD', 'ALL', 'ALTER', 'AND', 'AS', 'AUTOINCREMENT',
'BETWEEN', 'BY',
'CASE', 'CHECK', 'COLLATE', 'COLUMN', 'COMMIT', 'CONSTRAINT', 'CREATE', 'CROSS',
'DEFAULT', 'DEFERRABLE', 'DELETE', 'DISTINCT', 'DROP',
'ELSE', 'ESCAPE', 'EXCEPT', 'EXISTS',
'FOREIGN', 'FROM', 'FULL',
'GROUP',
'HAVING',
'IN', 'INDEX', 'INNER', 'INSERT', 'INTERSECT', 'INTO', 'IS', 'ISNULL',
'JOIN',
'LEFT', 'LIMIT',
'NATURAL', 'NOT', 'NOTNULL', 'NULL',
'ON', 'OR', 'ORDER', 'OUTER',
'PRIMARY',
'REFERENCES', 'REGEXP', 'RIGHT', 'ROLLBACK',
'SELECT', 'SET',
'TABLE', 'THEN', 'TO', 'TRANSACTION',
'UNION', 'UNIQUE', 'UPDATE', 'USING',
'VALUES',
'WHEN', 'WHERE',
);
return $reserved_words;
}
public function addslashes($s) {
// do not use php addslashes() because it depends on PHP quote settings!
$s = str_replace("'", "''", $s);
return $s;
}
}