Subversion-Projekte lars-tiefland.prado

<?php

/**

 * TSqliteMetaData class file.

 *

 * @author Wei Zhuo <weizhuo[at]gmail[dot]com>

 * @link http://www.pradosoft.com/

 * @copyright Copyright © 2005-2008 PradoSoft

 * @license http://www.pradosoft.com/license/

 * @version $Id: TSqliteMetaData.php 1861 2007-04-12 08:05:03Z wei $

 * @package System.Data.Common.Sqlite

 */

/**

 * Load the base TDbMetaData class.

 */

Prado::using('System.Data.Common.TDbMetaData');

Prado::using('System.Data.Common.Sqlite.TSqliteTableInfo');

/**

 * TSqliteMetaData loads SQLite database table and column information.

 *

 * @author Wei Zhuo <weizho[at]gmail[dot]com>

 * @version $Id: TSqliteMetaData.php 1861 2007-04-12 08:05:03Z wei $

 * @package System.Data.Commom.Sqlite

 * @since 3.1

 */

class TSqliteMetaData extends TDbMetaData

{

	/**

	 * @return string TDbTableInfo class name.

	 */

	protected function getTableInfoClass()

	{

		return 'TSqliteTableInfo';

	}

	/**

	 * Get the column definitions for given table.

	 * @param string table name.

	 * @return TPgsqlTableInfo table information.

	 */

	protected function createTableInfo($tableName)

	{

		$tableName = str_replace("'",'',$tableName);

		$this->getDbConnection()->setActive(true);

		$table = $this->getDbConnection()->quoteString($tableName);

		$sql = "PRAGMA table_info({$table})";

		$command = $this->getDbConnection()->createCommand($sql);

		$foreign = $this->getForeignKeys($table);

		$index=0;

		$columns=array();

		$primary=array();

		foreach($command->query() as $col)

		{

			$col['index'] = $index++;

			$column = $this->processColumn($col, $foreign);

			$columns[$col['name']] = $column;

			if($column->getIsPrimaryKey())

				$primary[] = $col['name'];

		}

		$info['TableName'] = $tableName;

		if($this->getIsView($tableName))

			$info['IsView'] = true;

		if(count($columns)===0)

			throw new TDbException('dbmetadata_invalid_table_view', $tableName);

		$class = $this->getTableInfoClass();

		$tableInfo = new $class($info,$primary,$foreign);

		$tableInfo->getColumns()->copyFrom($columns);

		return $tableInfo;

	}

	/**

	 * @param string table name.

	 * @return boolean true if the table is a view.

	 */

	protected function getIsView($tableName)

	{

		$sql = 'SELECT count(*) FROM sqlite_master WHERE type="view" AND name= :table';

		$this->getDbConnection()->setActive(true);

		$command = $this->getDbConnection()->createCommand($sql);

		$command->bindValue(':table', $tableName);

		return intval($command->queryScalar()) === 1;

	}

	/**

	 * @param array column information.

	 * @param array foreign key details.

	 * @return TSqliteTableColumn column details.

	 */

	protected function processColumn($col, $foreign)

	{

		$columnId = $col['name']; //use column name as column Id

		$info['ColumnName'] = '"'.$columnId.'"'; //quote the column names!

		$info['ColumnId'] = $columnId;

		$info['ColumnIndex'] = $col['index'];

		if($col['notnull']!=='99')

			$info['AllowNull'] = true;

		if($col['pk']==='1')

			$info['IsPrimaryKey'] = true;

		if($this->isForeignKeyColumn($columnId, $foreign))

			$info['IsForeignKey'] = true;

		if($col['dflt_value']!==null)

			$info['DefaultValue'] = $col['dflt_value'];

		$type = strtolower($col['type']);

		$info['AutoIncrement'] = $type==='integer' && $col['pk']==='1';

		$info['DbType'] = $type;

		$match=array();

		if(is_int($pos=strpos($type, '(')) && preg_match('/\((.*)\)/', $type, $match))

		{

			$ps = explode(',', $match[1]);

			if(count($ps)===2)

			{

				$info['NumericPrecision'] = intval($ps[0]);

				$info['NumericScale'] = intval($ps[1]);

			}

			else

				$info['ColumnSize']=intval($match[1]);

			$info['DbType'] = substr($type,0,$pos);

		}

		return new TSqliteTableColumn($info);

	}

	/**

	 *

	 *

	 * @param string quoted table name.

	 * @return array foreign key details.

	 */

	protected function getForeignKeys($table)

	{

		$sql = "PRAGMA foreign_key_list({$table})";

		$command = $this->getDbConnection()->createCommand($sql);

		$fkeys = array();

		foreach($command->query() as $col)

		{

			$fkeys[$col['table']]['keys'][$col['from']] = $col['to'];

			$fkeys[$col['table']]['table'] = $col['table'];

		}

		return count($fkeys) > 0 ? array_values($fkeys) : $fkeys;

	}

	/**

	 * @param string column name.

	 * @param array foreign key column names.

	 * @return boolean true if column is a foreign key.

	 */

	protected function isForeignKeyColumn($columnId, $foreign)

	{

		foreach($foreign as $fk)

		{

			if(in_array($columnId, array_keys($fk['keys'])))

				return true;

		}

		return false;

	}

}

/**

CREATE TABLE foo

(

	id INTEGER NOT NULL PRIMARY KEY,

	id2 CHAR(2)

);

CREATE TABLE bar

(

	id INTEGER NOT NULL PRIMARY KEY,

	foo_id INTEGER

		CONSTRAINT fk_foo_id REFERENCES foo(id) ON DELETE CASCADE

);

*/