* $schema = ezcDbSchema::createFromFile( 'array', 'file.php' );
* $schema->writeToFile( 'xml', 'file.xml' );
*
*
* The following example shows how you can load a database schema
* from the XML format and store it into a database.
*
* $db = ezcDbFactory::create( 'mysql://user:password@host/database' );
* $schema = ezcDbSchema::createFromFile( 'xml', 'file.php' );
* $schema->writeToDb( $db );
*
*
* Examples that shows how to make a comparison between a file on disk and a
* database, and how to apply the changes.
*
* $xmlSchema = ezcDbSchema::createFromFile( 'xml', 'wanted-schema.xml' );
* $dbSchema = ezcDbSchema::createFromDb( $db );
* $diff = ezcDbSchemaComparator::compareSchemas( $xmlSchema, $dbSchema );
* $diff->applyToDb( $db );
*
*
* @package DatabaseSchema
* @version 1.0rc1
*/
class ezcDbSchema
{
/**
* Used by reader and writer classes to inform that it implements a file
* based handler.
*/
const FILE = 1;
/**
* Used by reader and writer classes to inform that it implements a
* database based handler.
*/
const DATABASE = 2;
/**
* Stores the schema information.
*
* @var array(string=>ezcDbSchemaTable)
*/
private $schema;
/**
* Meant to store data - not currently in use
*
* @var array
*/
private $data;
/**
* A list of all the supported database filed types
*
* @var array(string)
*/
static public $supportedTypes = array(
'integer', 'boolean', 'float', 'decimal', 'timestamp', 'time', 'date',
'text', 'blob', 'clob'
);
/**
* Constructs a new ezcDbSchema object with schema definition $schema.
*
* @param array(ezcDbSchemaTable) $schema
* @param array $data
*/
public function __construct( array $schema, $data = array() )
{
$this->schema = $schema;
$this->data = $data;
}
/**
* Checks whether the object in $obj implements the correct $type of reader handler.
*
* @throws ezcDbSchemaInvalidReaderClassException if the object in $obj is
* not a schema reader of the correct type.
*
* @param ezcDbSchemaReader $obj
* @param int $type
*/
static private function checkSchemaReader( ezcDbSchemaReader $obj, $type )
{
if ( !( ( $obj->getReaderType() & $type ) == $type ) )
{
throw new ezcDbSchemaInvalidReaderClassException( get_class( $obj ), $type );
}
}
/**
* Factory method to create a ezcDbSchema object from the file $file with the format $format.
*
* @throws ezcDbSchemaInvalidReaderClassException if the handler associated
* with the $format is not a file schema reader.
*
* @param string $format
* @param string $file
*/
static public function createFromFile( $format, $file )
{
$className = ezcDbSchemaHandlerManager::getReaderByFormat( $format );
$reader = new $className();
self::checkSchemaReader( $reader, self::FILE );
return $reader->loadFromFile( $file );
}
/**
* Factory method to create a ezcDbSchema object from the database $db.
*
* @throws ezcDbSchemaInvalidReaderClassException if the handler associated
* with the $format is not a database schema reader.
*
* @param ezcDbHandler $db
*/
static public function createFromDb( ezcDbHandler $db )
{
$className = ezcDbSchemaHandlerManager::getReaderByFormat( $db->getName() );
$reader = new $className();
self::checkSchemaReader( $reader, self::DATABASE );
return $reader->loadFromDb( $db );
}
/**
* Checks whether the object in $obj implements the correct $type of writer handler.
*
* @throws ezcDbSchemaInvalidWriterClassException if the object in $obj is
* not a schema writer of the correct type.
*
* @param ezcDbSchemaWriter $obj
* @param int $type
*/
static private function checkSchemaWriter( $obj, $type )
{
if ( !( ( $obj->getWriterType() & $type ) == $type ) )
{
throw new ezcDbSchemaInvalidWriterClassException( get_class( $obj ), $type );
}
}
/**
* Writes the schema to the file $file in format $format.
*
* @throws ezcDbSchemaInvalidWriterClassException if the handler associated
* with the $format is not a file schema writer.
*
* @param string $format
* @param string $file
*/
public function writeToFile( $format, $file )
{
$className = ezcDbSchemaHandlerManager::getWriterByFormat( $format );
$reader = new $className();
self::checkSchemaWriter( $reader, self::FILE );
$reader->saveToFile( $file, $this );
}
/**
* Creates the tables defined in the schema into the database specified through $db.
*
* @throws ezcDbSchemaInvalidWriterClassException if the handler associated
* with the $format is not a database schema writer.
*
* @param ezcDbHandler $db
*/
public function writeToDb( ezcDbHandler $db )
{
$className = ezcDbSchemaHandlerManager::getWriterByFormat( $db->getName() );
$writer = new $className();
self::checkSchemaWriter( $writer, self::DATABASE );
$writer->saveToDb( $db, $this );
}
/**
* Returns the $db specific SQL queries that would create the tables defined in the schema.
*
* @throws ezcDbSchemaInvalidWriterClassException if the handler associated
* with the $format is not a database schema writer.
*
* @param ezcDbHandler $db
* @return array(string)
*/
public function convertToDDL( ezcDbHandler $db )
{
$className = ezcDbSchemaHandlerManager::getWriterByFormat( $db->getName() );
$writer = new $className();
self::checkSchemaWriter( $writer, self::DATABASE );
return $writer->convertToDDL( $this );
}
/**
* Returns the internal schema.
*
* @return array(string=>ezcDbSchemaTable)
*/
public function getSchema()
{
return $this->schema;
}
/**
* Returns the internal data.
*
* This data is not used anywhere though.
*
* @return array
*/
public function getData()
{
return $this->data;
}
}
?>