<?php
/**
* CDbSchema 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/
*/
/**
* CDbSchema is the base class for retrieving metadata information.
*
* @author Qiang Xue <[email protected]>
* @version $Id: CDbSchema.php 3297 2011-06-22 21:46:11Z qiang.xue $
* @package system.db.schema
* @since 1.0
*/
abstract class CDbSchema extends CComponent
{
/**
* @var array the abstract column types mapped to physical column types.
* @since 1.1.6
*/
public $columnTypes=array();
private $_tableNames=array();
private $_tables=array();
private $_connection;
private $_builder;
private $_cacheExclude=array();
/**
* Loads the metadata for the specified table.
* @param string $name table name
* @return CDbTableSchema driver dependent table metadata, null if the table does not exist.
*/
abstract protected function loadTable($name);
/**
* Constructor.
* @param CDbConnection $conn database connection.
*/
public function __construct($conn)
{
$this->_connection=$conn;
foreach($conn->schemaCachingExclude as $name)
$this->_cacheExclude[$name]=true;
}
/**
* @return CDbConnection database connection. The connection is active.
*/
public function getDbConnection()
{
return $this->_connection;
}
/**
* Obtains the metadata for the named table.
* @param string $name table name
* @return CDbTableSchema table metadata. Null if the named table does not exist.
*/
public function getTable($name)
{
if(isset($this->_tables[$name]))
return $this->_tables[$name];
else
{
if($this->_connection->tablePrefix!==null && strpos($name,'{{')!==false)
$realName=preg_replace('/\{\{(.*?)\}\}/',$this->_connection->tablePrefix.'$1',$name);
else
$realName=$name;
// temporarily disable query caching
if($this->_connection->queryCachingDuration>0)
{
$qcDuration=$this->_connection->queryCachingDuration;
$this->_connection->queryCachingDuration=0;
}
if(!isset($this->_cacheExclude[$name]) && ($duration=$this->_connection->schemaCachingDuration)>0 && $this->_connection->schemaCacheID!==false && ($cache=Yii::app()->getComponent($this->_connection->schemaCacheID))!==null)
{
$key='yii:dbschema'.$this->_connection->connectionString.':'.$this->_connection->username.':'.$name;
if(($table=$cache->get($key))===false)
{
$table=$this->loadTable($realName);
if($table!==null)
$cache->set($key,$table,$duration);
}
$this->_tables[$name]=$table;
}
else
$this->_tables[$name]=$table=$this->loadTable($realName);
if(isset($qcDuration)) // re-enable query caching
$this->_connection->queryCachingDuration=$qcDuration;
return $table;
}
}
/**
* Returns the metadata for all tables in the database.
* @param string $schema the schema of the tables. Defaults to empty string, meaning the current or default schema.
* @return array the metadata for all tables in the database.
* Each array element is an instance of {@link CDbTableSchema} (or its child class).
* The array keys are table names.
* @since 1.0.2
*/
public function getTables($schema='')
{
$tables=array();
foreach($this->getTableNames($schema) as $name)
{
if(($table=$this->getTable($name))!==null)
$tables[$name]=$table;
}
return $tables;
}
/**
* Returns all table names in the database.
* @param string $schema the schema of the tables. Defaults to empty string, meaning the current or default schema.
* If not empty, the returned table names will be prefixed with the schema name.
* @return array all table names in the database.
* @since 1.0.2
*/
public function getTableNames($schema='')
{
if(!isset($this->_tableNames[$schema]))
$this->_tableNames[$schema]=$this->findTableNames($schema);
return $this->_tableNames[$schema];
}
/**
* @return CDbCommandBuilder the SQL command builder for this connection.
*/
public function getCommandBuilder()
{
if($this->_builder!==null)
return $this->_builder;
else
return $this->_builder=$this->createCommandBuilder();
}
/**
* Refreshes the schema.
* This method resets the loaded table metadata and command builder
* so that they can be recreated to reflect the change of schema.
*/
public function refresh()
{
if(($duration=$this->_connection->schemaCachingDuration)>0 && $this->_connection->schemaCacheID!==false && ($cache=Yii::app()->getComponent($this->_connection->schemaCacheID))!==null)
{
foreach(array_keys($this->_tables) as $name)
{
if(!isset($this->_cacheExclude[$name]))
{
$key='yii:dbschema'.$this->_connection->connectionString.':'.$this->_connection->username.':'.$name;
$cache->delete($key);
}
}
}
$this->_tables=array();
$this->_tableNames=array();
$this->_builder=null;
}
/**
* Quotes a table name for use in a query.
* If the table name contains schema prefix, the prefix will also be properly quoted.
* @param string $name table name
* @return string the properly quoted table name
* @see quoteSimpleTableName
*/
public function quoteTableName($name)
{
if(strpos($name,'.')===false)
return $this->quoteSimpleTableName($name);
$parts=explode('.',$name);
foreach($parts as $i=>$part)
$parts[$i]=$this->quoteSimpleTableName($part);
return implode('.',$parts);
}
/**
* Quotes a simple table name for use in a query.
* A simple table name does not schema prefix.
* @param string $name table name
* @return string the properly quoted table name
* @since 1.1.6
*/
public function quoteSimpleTableName($name)
{
return "'".$name."'";
}
/**
* Quotes a column name for use in a query.
* If the column name contains prefix, the prefix will also be properly quoted.
* @param string $name column name
* @return string the properly quoted column name
* @see quoteSimpleColumnName
*/
public function quoteColumnName($name)
{
if(($pos=strrpos($name,'.'))!==false)
{
$prefix=$this->quoteTableName(substr($name,0,$pos)).'.';
$name=substr($name,$pos+1);
}
else
$prefix='';
return $prefix . ($name==='*' ? $name : $this->quoteSimpleColumnName($name));
}
/**
* Quotes a simple column name for use in a query.
* A simple column name does not contain prefix.
* @param string $name column name
* @return string the properly quoted column name
* @since 1.1.6
*/
public function quoteSimpleColumnName($name)
{
return '"'.$name.'"';
}
/**
* Compares two table names.
* The table names can be either quoted or unquoted. This method
* will consider both cases.
* @param string $name1 table name 1
* @param string $name2 table name 2
* @return boolean whether the two table names refer to the same table.
*/
public function compareTableNames($name1,$name2)
{
$name1=str_replace(array('"','`',"'"),'',$name1);
$name2=str_replace(array('"','`',"'"),'',$name2);
if(($pos=strrpos($name1,'.'))!==false)
$name1=substr($name1,$pos+1);
if(($pos=strrpos($name2,'.'))!==false)
$name2=substr($name2,$pos+1);
if($this->_connection->tablePrefix!==null)
{
if(strpos($name1,'{')!==false)
$name1=$this->_connection->tablePrefix.str_replace(array('{','}'),'',$name1);
if(strpos($name2,'{')!==false)
$name2=$this->_connection->tablePrefix.str_replace(array('{','}'),'',$name2);
}
return $name1===$name2;
}
/**
* 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)
{
}
/**
* 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,$schema='')
{
}
/**
* Creates a command builder for the database.
* This method may be overridden by child classes to create a DBMS-specific command builder.
* @return CDbCommandBuilder command builder instance
*/
protected function createCommandBuilder()
{
return new CDbCommandBuilder($this);
}
/**
* Returns all table names in the database.
* This method should be overridden by child classes in order to support this feature
* because the default implementation simply throws an exception.
* @param string $schema the schema of the tables. Defaults to empty string, meaning the current or default schema.
* If not empty, the returned table names will be prefixed with the schema name.
* @return array all table names in the database.
* @since 1.0.2
*/
protected function findTableNames($schema='')
{
throw new CDbException(Yii::t('yii','{class} does not support fetching all table names.',
array('{class}'=>get_class($this))));
}
/**
* Converts an abstract column type into a physical column type.
* The conversion is done using the type map specified in {@link columnTypes}.
* These abstract column types are supported (using MySQL as example to explain the corresponding
* physical types):
* <ul>
* <li>pk: an auto-incremental primary key type, will be converted into "int(11) NOT NULL AUTO_INCREMENT PRIMARY KEY"</li>
* <li>string: string type, will be converted into "varchar(255)"</li>
* <li>text: a long string type, will be converted into "text"</li>
* <li>integer: integer type, will be converted into "int(11)"</li>
* <li>boolean: boolean type, will be converted into "tinyint(1)"</li>
* <li>float: float number type, will be converted into "float"</li>
* <li>decimal: decimal number type, will be converted into "decimal"</li>
* <li>datetime: datetime type, will be converted into "datetime"</li>
* <li>timestamp: timestamp type, will be converted into "timestamp"</li>
* <li>time: time type, will be converted into "time"</li>
* <li>date: date type, will be converted into "date"</li>
* <li>binary: binary data type, will be converted into "blob"</li>
* </ul>
*
* If the abstract type contains two or more parts separated by spaces (e.g. "string NOT NULL"), then only
* the first part will be converted, and the rest of the parts will be appended to the conversion result.
* For example, 'string NOT NULL' is converted to 'varchar(255) NOT NULL'.
* @param string $type abstract column type
* @return string physical column type.
* @since 1.1.6
*/
public function getColumnType($type)
{
if(isset($this->columnTypes[$type]))
return $this->columnTypes[$type];
else if(($pos=strpos($type,' '))!==false)
{
$t=substr($type,0,$pos);
return (isset($this->columnTypes[$t]) ? $this->columnTypes[$t] : $t).substr($type,$pos);
}
else
return $type;
}
/**
* Builds a SQL statement for creating a new DB table.
*
* The columns in the new table should be specified as name-definition pairs (e.g. 'name'=>'string'),
* where name stands for a column name which will be properly quoted by the method, and definition
* stands for the column type which can contain an abstract DB type.
* The {@link getColumnType} method will be invoked to convert any abstract type into a physical one.
*
* If a column is specified with definition only (e.g. 'PRIMARY KEY (name, type)'), it will be directly
* inserted into the generated SQL.
*
* @param string $table the name of the table to be created. The name will be properly quoted by the method.
* @param array $columns the columns (name=>definition) in the new table.
* @param string $options additional SQL fragment that will be appended to the generated SQL.
* @return string the SQL statement for creating a new DB table.
* @since 1.1.6
*/
public function createTable($table, $columns, $options=null)
{
$cols=array();
foreach($columns as $name=>$type)
{
if(is_string($name))
$cols[]="\t".$this->quoteColumnName($name).' '.$this->getColumnType($type);
else
$cols[]="\t".$type;
}
$sql="CREATE TABLE ".$this->quoteTableName($table)." (\n".implode(",\n",$cols)."\n)";
return $options===null ? $sql : $sql.' '.$options;
}
/**
* Builds a SQL statement for renaming a DB table.
* @param string $table the table to be renamed. The name will be properly quoted by the method.
* @param string $newName the new table name. The name will be properly quoted by the method.
* @return string the SQL statement for renaming a DB table.
* @since 1.1.6
*/
public function renameTable($table, $newName)
{
return 'RENAME TABLE ' . $this->quoteTableName($table) . ' TO ' . $this->quoteTableName($newName);
}
/**
* Builds a SQL statement for dropping a DB table.
* @param string $table the table to be dropped. The name will be properly quoted by the method.
* @return string the SQL statement for dropping a DB table.
* @since 1.1.6
*/
public function dropTable($table)
{
return "DROP TABLE ".$this->quoteTableName($table);
}
/**
* 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 "TRUNCATE TABLE ".$this->quoteTableName($table);
}
/**
* Builds a SQL statement for adding a new DB column.
* @param string $table the table that the new column will be added to. The table name will be properly quoted by the method.
* @param string $column the name of the new column. The name will be properly quoted by the method.
* @param string $type the column type. The {@link getColumnType} method will be invoked to convert abstract column type (if any)
* into the physical one. Anything that is not recognized as abstract type will be kept in the generated SQL.
* For example, 'string' will be turned into 'varchar(255)', while 'string not null' will become 'varchar(255) not null'.
* @return string the SQL statement for adding a new column.
* @since 1.1.6
*/
public function addColumn($table, $column, $type)
{
$type=$this->getColumnType($type);
$sql='ALTER TABLE ' . $this->quoteTableName($table)
. ' ADD ' . $this->quoteColumnName($column) . ' '
. $this->getColumnType($type);
return $sql;
}
/**
* Builds a SQL statement for dropping a DB column.
* @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, $column)
{
return "ALTER TABLE ".$this->quoteTableName($table)
." DROP COLUMN ".$this->quoteColumnName($column);
}
/**
* Builds a SQL statement for renaming a column.
* @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, $newName)
{
return "ALTER TABLE ".$this->quoteTableName($table)
. " RENAME COLUMN ".$this->quoteColumnName($name)
. " TO ".$this->quoteColumnName($newName);
}
/**
* Builds a SQL statement for changing the definition of a column.
* @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)
{
$type=$this->getColumnType($type);
return 'ALTER TABLE ' . $this->quoteTableName($table) . ' CHANGE '
. $this->quoteColumnName($column) . ' '
. $this->quoteColumnName($column) . ' '
. $this->getColumnType($type);
}
/**
* Builds a SQL statement for adding a foreign key constraint to an existing table.
* The method will properly quote the table and column names.
* @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)
{
$columns=preg_split('/\s*,\s*/',$columns,-1,PREG_SPLIT_NO_EMPTY);
foreach($columns as $i=>$col)
$columns[$i]=$this->quoteColumnName($col);
$refColumns=preg_split('/\s*,\s*/',$refColumns,-1,PREG_SPLIT_NO_EMPTY);
foreach($refColumns as $i=>$col)
$refColumns[$i]=$this->quoteColumnName($col);
$sql='ALTER TABLE '.$this->quoteTableName($table)
.' ADD CONSTRAINT '.$this->quoteColumnName($name)
.' FOREIGN KEY ('.implode(', ', $columns).')'
.' REFERENCES '.$this->quoteTableName($refTable)
.' ('.implode(', ', $refColumns).')';
if($delete!==null)
$sql.=' ON DELETE '.$delete;
if($update!==null)
$sql.=' ON UPDATE '.$update;
return $sql;
}
/**
* Builds a SQL statement for dropping a foreign key constraint.
* @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, $table)
{
return 'ALTER TABLE '.$this->quoteTableName($table)
.' DROP CONSTRAINT '.$this->quoteColumnName($name);
}
/**
* Builds a SQL statement for creating a new index.
* @param string $name the name of the index. The name will be properly quoted by the method.
* @param string $table the table that the new index will be created for. The table name will be properly quoted by the method.
* @param string $column the column(s) that should be included in the index. If there are multiple columns, please separate them
* by commas. Each column name will be properly quoted by the method, unless a parenthesis is found in the name.
* @param boolean $unique whether to add UNIQUE constraint on the created index.
* @return string the SQL statement for creating a new index.
* @since 1.1.6
*/
public function createIndex($name, $table, $column, $unique=false)
{
$cols=array();
$columns=preg_split('/\s*,\s*/',$column,-1,PREG_SPLIT_NO_EMPTY);
foreach($columns as $col)
{
if(strpos($col,'(')!==false)
$cols[]=$col;
else
$cols[]=$this->quoteColumnName($col);
}
return ($unique ? 'CREATE UNIQUE INDEX ' : 'CREATE INDEX ')
. $this->quoteTableName($name).' ON '
. $this->quoteTableName($table).' ('.implode(', ',$cols).')';
}
/**
* 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($name).' ON '.$this->quoteTableName($table);
}
}