<?php
/**
* CSqliteSchema class file.
*
* @author Qiang Xue <[email protected]>
* @link http://www.yiiframework.com/
* @copyright Copyright © 2008-2011 Yii Software LLC
* @license http://www.yiiframework.com/license/
*/
/**
* CSqliteSchema is the class for retrieving metadata information from a SQLite (2/3) database.
*
* @author Qiang Xue <[email protected]>
* @version $Id: CSqliteSchema.php 3304 2011-06-23 14:53:50Z qiang.xue $
* @package system.db.schema.sqlite
* @since 1.0
*/
class CSqliteSchema extends CDbSchema
{
/**
* @var array the abstract column types mapped to physical column types.
* @since 1.1.6
*/
public $columnTypes=array(
'pk' => 'integer PRIMARY KEY AUTOINCREMENT NOT NULL',
'string' => 'varchar(255)',
'text' => 'text',
'integer' => 'integer',
'float' => 'float',
'decimal' => 'decimal',
'datetime' => 'datetime',
'timestamp' => 'timestamp',
'time' => 'time',
'date' => 'date',
'binary' => 'blob',
'boolean' => 'tinyint(1)',
'money' => 'decimal(19,4)',
);
/**
* Resets the sequence value of a table's primary key.
* The sequence will be reset such that the primary key of the next new row inserted
* will have the specified value or 1.
* @param CDbTableSchema $table the table schema whose primary key sequence will be reset
* @param mixed $value the value for the primary key of the next new row inserted. If this is not set,
* the next new row's primary key will have a value 1.
* @since 1.1
*/
public function resetSequence($table,$value=null)
{
if($table->sequenceName!==null)
{
if($value===null)
$value=$this->getDbConnection()->createCommand("SELECT MAX(`{$table->primaryKey}`) FROM {$table->rawName}")->queryScalar();
else
$value=(int)$value-1;
try
{
// it's possible sqlite_sequence does not exist
$this->getDbConnection()->createCommand("UPDATE sqlite_sequence SET seq='$value' WHERE name='{$table->name}'")->execute();
}
catch(Exception $e)
{
}
}
}
/**
* Enables or disables integrity check.
* @param boolean $check whether to turn on or off the integrity check.
* @param string $schema the schema of the tables. Defaults to empty string, meaning the current or default schema.
* @since 1.1
*/
public function checkIntegrity($check=true,$schema='')
{
// SQLite doesn't enforce integrity
return;
}
/**
* Returns all table names in the database.
* @param string $schema the schema of the tables. This is not used for sqlite database.
* @return array all table names in the database.
* @since 1.0.2
*/
protected function findTableNames($schema='')
{
$sql="SELECT DISTINCT tbl_name FROM sqlite_master WHERE tbl_name<>'sqlite_sequence'";
return $this->getDbConnection()->createCommand($sql)->queryColumn();
}
/**
* Creates a command builder for the database.
* @return CSqliteCommandBuilder command builder instance
*/
protected function createCommandBuilder()
{
return new CSqliteCommandBuilder($this);
}
/**
* Loads the metadata for the specified table.
* @param string $name table name
* @return CDbTableSchema driver dependent table metadata. Null if the table does not exist.
*/
protected function loadTable($name)
{
$table=new CDbTableSchema;
$table->name=$name;
$table->rawName=$this->quoteTableName($name);
if($this->findColumns($table))
{
$this->findConstraints($table);
return $table;
}
else
return null;
}
/**
* Collects the table column metadata.
* @param CDbTableSchema $table the table metadata
* @return boolean whether the table exists in the database
*/
protected function findColumns($table)
{
$sql="PRAGMA table_info({$table->rawName})";
$columns=$this->getDbConnection()->createCommand($sql)->queryAll();
if(empty($columns))
return false;
foreach($columns as $column)
{
$c=$this->createColumn($column);
$table->columns[$c->name]=$c;
if($c->isPrimaryKey)
{
if($table->primaryKey===null)
$table->primaryKey=$c->name;
else if(is_string($table->primaryKey))
$table->primaryKey=array($table->primaryKey,$c->name);
else
$table->primaryKey[]=$c->name;
}
}
if(is_string($table->primaryKey) && !strncasecmp($table->columns[$table->primaryKey]->dbType,'int',3))
{
$table->sequenceName='';
$table->columns[$table->primaryKey]->autoIncrement=true;
}
return true;
}
/**
* Collects the foreign key column details for the given table.
* @param CDbTableSchema $table the table metadata
*/
protected function findConstraints($table)
{
$foreignKeys=array();
$sql="PRAGMA foreign_key_list({$table->rawName})";
$keys=$this->getDbConnection()->createCommand($sql)->queryAll();
foreach($keys as $key)
{
$column=$table->columns[$key['from']];
$column->isForeignKey=true;
$foreignKeys[$key['from']]=array($key['table'],$key['to']);
}
$table->foreignKeys=$foreignKeys;
}
/**
* Creates a table column.
* @param array $column column metadata
* @return CDbColumnSchema normalized column metadata
*/
protected function createColumn($column)
{
$c=new CSqliteColumnSchema;
$c->name=$column['name'];
$c->rawName=$this->quoteColumnName($c->name);
$c->allowNull=!$column['notnull'];
$c->isPrimaryKey=$column['pk']!=0;
$c->isForeignKey=false;
$c->init(strtolower($column['type']),$column['dflt_value']);
return $c;
}
/**
* Builds a SQL statement for truncating a DB table.
* @param string $table the table to be truncated. The name will be properly quoted by the method.
* @return string the SQL statement for truncating a DB table.
* @since 1.1.6
*/
public function truncateTable($table)
{
return "DELETE FROM ".$this->quoteTableName($table);
}
/**
* Builds a SQL statement for dropping a DB column.
* Because SQLite does not support dropping a DB column, calling this method will throw an exception.
* @param string $table the table whose column is to be dropped. The name will be properly quoted by the method.
* @param string $column the name of the column to be dropped. The name will be properly quoted by the method.
* @return string the SQL statement for dropping a DB column.
* @since 1.1.6
*/
public function dropColumn($table, $column)
{
throw new CDbException(Yii::t('yii', 'Dropping DB column is not supported by SQLite.'));
}
/**
* Builds a SQL statement for renaming a column.
* Because SQLite does not support renaming a DB column, calling this method will throw an exception.
* @param string $table the table whose column is to be renamed. The name will be properly quoted by the method.
* @param string $name the old name of the column. The name will be properly quoted by the method.
* @param string $newName the new name of the column. The name will be properly quoted by the method.
* @return string the SQL statement for renaming a DB column.
* @since 1.1.6
*/
public function renameColumn($table, $name, $newName)
{
throw new CDbException(Yii::t('yii', 'Renaming a DB column is not supported by SQLite.'));
}
/**
* Builds a SQL statement for adding a foreign key constraint to an existing table.
* Because SQLite does not support adding foreign key to an existing table, calling this method will throw an exception.
* @param string $name the name of the foreign key constraint.
* @param string $table the table that the foreign key constraint will be added to.
* @param string $columns the name of the column to that the constraint will be added on. If there are multiple columns, separate them with commas.
* @param string $refTable the table that the foreign key references to.
* @param string $refColumns the name of the column that the foreign key references to. If there are multiple columns, separate them with commas.
* @param string $delete the ON DELETE option. Most DBMS support these options: RESTRICT, CASCADE, NO ACTION, SET DEFAULT, SET NULL
* @param string $update the ON UPDATE option. Most DBMS support these options: RESTRICT, CASCADE, NO ACTION, SET DEFAULT, SET NULL
* @return string the SQL statement for adding a foreign key constraint to an existing table.
* @since 1.1.6
*/
public function addForeignKey($name, $table, $columns, $refTable, $refColumns, $delete=null, $update=null)
{
throw new CDbException(Yii::t('yii', 'Adding a foreign key constraint to an existing table is not supported by SQLite.'));
}
/**
* Builds a SQL statement for dropping a foreign key constraint.
* Because SQLite does not support dropping a foreign key constraint, calling this method will throw an exception.
* @param string $name the name of the foreign key constraint to be dropped. The name will be properly quoted by the method.
* @param string $table the table whose foreign is to be dropped. The name will be properly quoted by the method.
* @return string the SQL statement for dropping a foreign key constraint.
* @since 1.1.6
*/
public function dropForeignKey($name, $table)
{
throw new CDbException(Yii::t('yii', 'Dropping a foreign key constraint is not supported by SQLite.'));
}
/**
* Builds a SQL statement for changing the definition of a column.
* Because SQLite does not support altering a DB column, calling this method will throw an exception.
* @param string $table the table whose column is to be changed. The table name will be properly quoted by the method.
* @param string $column the name of the column to be changed. The name will be properly quoted by the method.
* @param string $type the new column type. The {@link getColumnType} method will be invoked to convert abstract column type (if any)
* into the physical one. Anything that is not recognized as abstract type will be kept in the generated SQL.
* For example, 'string' will be turned into 'varchar(255)', while 'string not null' will become 'varchar(255) not null'.
* @return string the SQL statement for changing the definition of a column.
* @since 1.1.6
*/
public function alterColumn($table, $column, $type)
{
throw new CDbException(Yii::t('yii', 'Altering a DB column is not supported by SQLite.'));
}
/**
* Builds a SQL statement for dropping an index.
* @param string $name the name of the index to be dropped. The name will be properly quoted by the method.
* @param string $table the table whose index is to be dropped. The name will be properly quoted by the method.
* @return string the SQL statement for dropping an index.
* @since 1.1.6
*/
public function dropIndex($name, $table)
{
return 'DROP INDEX '.$this->quoteTableName($name);
}
}