* @link http://www.yiiframework.com/ * @copyright 2008-2013 Yii Software LLC * @license http://www.yiiframework.com/license/ */ /** * CDbSchema is the base class for retrieving metadata information. * * @property CDbConnection $dbConnection Database connection. The connection is active. * @property array $tables 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. * @property array $tableNames All table names in the database. * @property CDbCommandBuilder $commandBuilder The SQL command builder for this connection. * * @author 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 * @param boolean $refresh if we need to refresh schema cache for a table. * Parameter available since 1.1.9 * @return CDbTableSchema table metadata. Null if the named table does not exist. */ public function getTable($name,$refresh=false) { if($refresh===false && 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; $table=$cache->get($key); if($refresh===true || $table===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 $schema the schema of the tables. Defaults to empty string, meaning the current or default schema. * @return array the metadata for all tables in the database. * Each array element is an instance of {@link CDbTableSchema} (or its child class). * The array keys are table names. */ public function getTables($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 $schema the schema of the tables. Defaults to empty string, meaning the current or default schema. * If not empty, the returned table names will be prefixed with the schema name. * @return array all table names in the database. */ public function getTableNames($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 max value of a primary key plus one (i.e. sequence trimming). * @param CDbTableSchema $table the table schema whose primary key sequence will be reset * @param integer|null $value the value for the primary key of the next new row inserted. * If this is not set, the next new row's primary key will have the max value of a primary * key plus one (i.e. sequence trimming). * @since 1.1 */ public function resetSequence($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 $schema the schema of the tables. Defaults to empty string, meaning the current or default schema. * If not empty, the returned table names will be prefixed with the schema name. * @throws CDbException if current schema does not support fetching all table names * @return array all table names in the database. */ protected function findTableNames($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): *

*
• pk: an auto-incremental primary key type, will be converted into "int(11) NOT NULL AUTO_INCREMENT PRIMARY KEY"
*
• string: string type, will be converted into "varchar(255)"
*
• text: a long string type, will be converted into "text"
*
• integer: integer type, will be converted into "int(11)"
*
• boolean: boolean type, will be converted into "tinyint(1)"
*
• float: float number type, will be converted into "float"
*
• decimal: decimal number type, will be converted into "decimal"
*
• datetime: datetime type, will be converted into "datetime"
*
• timestamp: timestamp type, will be converted into "timestamp"
*
• time: time type, will be converted into "time"
*
• date: date type, will be converted into "date"
*
• binary: binary data type, will be converted into "blob"
*

* * 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; } /** * 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) { return 'ALTER TABLE ' . $this->quoteTableName($table) . ' ADD ' . $this->quoteColumnName($column) . ' ' . $this->getColumnType($type); } /** * 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) { 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); } /** * Builds a SQL statement for adding a primary key constraint to an existing table. * @param string $name the name of the primary key constraint. * @param string $table the table that the primary key constraint will be added to. * @param string|array $columns comma separated string or array of columns that the primary key will consist of. * Array value can be passed since 1.1.14. * @return string the SQL statement for adding a primary key constraint to an existing table. * @since 1.1.13 */ public function addPrimaryKey($name,$table,$columns) { if(is_string($columns)) $columns=preg_split('/\s*,\s*/',$columns,-1,PREG_SPLIT_NO_EMPTY); foreach($columns as $i=>$col) $columns[$i]=$this->quoteColumnName($col); return 'ALTER TABLE ' . $this->quoteTableName($table) . ' ADD CONSTRAINT ' . $this->quoteColumnName($name) . ' PRIMARY KEY (' . implode(', ', $columns). ' )'; } /** * Builds a SQL statement for removing a primary key constraint to an existing table. * @param string $name the name of the primary key constraint to be removed. * @param string $table the table that the primary key constraint will be removed from. * @return string the SQL statement for removing a primary key constraint from an existing table. * @since 1.1.13 */ public function dropPrimaryKey($name,$table) { return 'ALTER TABLE ' . $this->quoteTableName($table) . ' DROP CONSTRAINT ' . $this->quoteColumnName($name); } }