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<?php
/**
* Schema class file.
*
* @author Qiang Xue <qiang.xue@gmail.com>
* @link http://www.yiiframework.com/
* @copyright Copyright &copy; 2008-2011 Yii Software LLC
* @license http://www.yiiframework.com/license/
*/
namespace yii\db\dao;
/**
* Schema is the base class for retrieving metadata information.
*
* @author Qiang Xue <qiang.xue@gmail.com>
* @since 2.0
*/
abstract class Schema extends \yii\base\Component
{
/**
* @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 $conn database connection.
*/
public function __construct($connection)
{
$this->_connection = $connection;
foreach ($connection->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];
elseif (($pos = strpos($type, ' ')) !== false)
{
$t = substr($type, 0, $pos);
return (isset($this->columnTypes[$t]) ? $this->columnTypes[$t] : $t) . substr($type, $pos);
}
else
return $type;
}
}