CDbMigration
Package | system.db |
---|---|
Inheritance | abstract class CDbMigration » CComponent |
Since | 1.1.6 |
Source Code | framework/db/CDbMigration.php |
CDbMigration is designed to be used together with the "yiic migrate" command.
Each child class of CDbMigration represents an individual database migration which is identified by the child class name.
Within each migration, the up method contains the logic for "upgrading" the database used in an application; while the down method contains "downgrading" logic. The "yiic migrate" command manages all available migrations in an application.
By overriding safeUp or safeDown methods instead of up and down the migration logic will be wrapped with a DB transaction.
CDbMigration provides a set of convenient methods for manipulating database data and schema. For example, the insert method can be used to easily insert a row of data into a database table; the createTable method can be used to create a database table. Compared with the same methods in CDbCommand, these methods will display extra information showing the method parameters and execution time, which may be useful when applying migrations.
Public Properties
Property | Type | Description | Defined By |
---|---|---|---|
dbConnection | CDbConnection | Returns the currently active database connection. | CDbMigration |
Public Methods
Method | Description | Defined By |
---|---|---|
__call() | Calls the named method which is not a class method. | CComponent |
__get() | Returns a property value, an event handler list or a behavior based on its name. | CComponent |
__isset() | Checks if a property value is null. | CComponent |
__set() | Sets value of a component property. | CComponent |
__unset() | Sets a component property to be null. | CComponent |
addColumn() | Builds and executes a SQL statement for adding a new DB column. | CDbMigration |
addForeignKey() | Builds a SQL statement for adding a foreign key constraint to an existing table. | CDbMigration |
addPrimaryKey() | Builds and executes a SQL statement for creating a primary key, supports composite primary keys. | CDbMigration |
alterColumn() | Builds and executes a SQL statement for changing the definition of a column. | CDbMigration |
asa() | Returns the named behavior object. | CComponent |
attachBehavior() | Attaches a behavior to this component. | CComponent |
attachBehaviors() | Attaches a list of behaviors to the component. | CComponent |
attachEventHandler() | Attaches an event handler to an event. | CComponent |
canGetProperty() | Determines whether a property can be read. | CComponent |
canSetProperty() | Determines whether a property can be set. | CComponent |
createIndex() | Builds and executes a SQL statement for creating a new index. | CDbMigration |
createTable() | Builds and executes a SQL statement for creating a new DB table. | CDbMigration |
delete() | Creates and executes a DELETE SQL statement. | CDbMigration |
detachBehavior() | Detaches a behavior from the component. | CComponent |
detachBehaviors() | Detaches all behaviors from the component. | CComponent |
detachEventHandler() | Detaches an existing event handler. | CComponent |
disableBehavior() | Disables an attached behavior. | CComponent |
disableBehaviors() | Disables all behaviors attached to this component. | CComponent |
down() | This method contains the logic to be executed when removing this migration. | CDbMigration |
dropColumn() | Builds and executes a SQL statement for dropping a DB column. | CDbMigration |
dropForeignKey() | Builds a SQL statement for dropping a foreign key constraint. | CDbMigration |
dropIndex() | Builds and executes a SQL statement for dropping an index. | CDbMigration |
dropPrimaryKey() | Builds and executes a SQL statement for removing a primary key, supports composite primary keys. | CDbMigration |
dropTable() | Builds and executes a SQL statement for dropping a DB table. | CDbMigration |
enableBehavior() | Enables an attached behavior. | CComponent |
enableBehaviors() | Enables all behaviors attached to this component. | CComponent |
evaluateExpression() | Evaluates a PHP expression or callback under the context of this component. | CComponent |
execute() | Executes a SQL statement. | CDbMigration |
getDbConnection() | Returns the currently active database connection. | CDbMigration |
getEventHandlers() | Returns the list of attached event handlers for an event. | CComponent |
hasEvent() | Determines whether an event is defined. | CComponent |
hasEventHandler() | Checks whether the named event has attached handlers. | CComponent |
hasProperty() | Determines whether a property is defined. | CComponent |
insert() | Creates and executes an INSERT SQL statement. | CDbMigration |
insertMultiple() | Creates and executes an INSERT SQL statement with multiple data. | CDbMigration |
raiseEvent() | Raises an event. | CComponent |
refreshTableSchema() | Refreshed schema cache for a table | CDbMigration |
renameColumn() | Builds and executes a SQL statement for renaming a column. | CDbMigration |
renameTable() | Builds and executes a SQL statement for renaming a DB table. | CDbMigration |
safeDown() | This method contains the logic to be executed when removing this migration. | CDbMigration |
safeUp() | This method contains the logic to be executed when applying this migration. | CDbMigration |
setDbConnection() | Sets the currently active database connection. | CDbMigration |
truncateTable() | Builds and executes a SQL statement for truncating a DB table. | CDbMigration |
up() | This method contains the logic to be executed when applying this migration. | CDbMigration |
update() | Creates and executes an UPDATE SQL statement. | CDbMigration |
Property Details
dbConnection property
public CDbConnection getDbConnection()
public void setDbConnection(CDbConnection $db)
Returns the currently active database connection. By default, the 'db' application component will be returned and activated. You can call setDbConnection to switch to a different database connection. Methods such as insert, createTable will use this database connection to perform DB queries.
Method Details
addColumn() method
public void addColumn(string $table, string $column, string $type) | ||
$table | string | the table that the new column will be added to. The table name will be properly quoted by the method. |
$column | string | the name of the new column. The name will be properly quoted by the method. |
$type | string | the column type. The getColumnType method will be invoked to convert abstract column type (if any) into the physical one. Anything that is not recognized as abstract type will be kept in the generated SQL. For example, 'string' will be turned into 'varchar(255)', while 'string not null' will become 'varchar(255) not null'. |
public function addColumn($table, $column, $type)
{
echo " > add column $column$type to table $table ...";
$time=microtime(true);
$this->getDbConnection()->createCommand()->addColumn($table, $column, $type);
echo " done (time: ".sprintf('%.3f', microtime(true)-$time)."s)\n";
}
Builds and executes a SQL statement for adding a new DB column.
addForeignKey() method
public void addForeignKey(string $name, string $table, string|array $columns, string $refTable, string|array $refColumns, string $delete=NULL, string $update=NULL) | ||
$name | string | the name of the foreign key constraint. |
$table | string | the table that the foreign key constraint will be added to. |
$columns | string|array | the name of the column to that the constraint will be added on. If there are multiple columns, separate them with commas or pass as an array of column names. |
$refTable | string | the table that the foreign key references to. |
$refColumns | string|array | the name of the column that the foreign key references to. If there are multiple columns, separate them with commas or pass as an array of column names. |
$delete | string | the ON DELETE option. Most DBMS support these options: RESTRICT, CASCADE, NO ACTION, SET DEFAULT, SET NULL |
$update | string | the ON UPDATE option. Most DBMS support these options: RESTRICT, CASCADE, NO ACTION, SET DEFAULT, SET NULL |
public function addForeignKey($name, $table, $columns, $refTable, $refColumns, $delete=null, $update=null)
{
echo " > add foreign key $name: $table (".(is_array($columns) ? implode(',', $columns) : $columns).
") references $refTable (".(is_array($refColumns) ? implode(',', $refColumns) : $refColumns).") ...";
$time=microtime(true);
$this->getDbConnection()->createCommand()->addForeignKey($name, $table, $columns, $refTable, $refColumns, $delete, $update);
echo " done (time: ".sprintf('%.3f', microtime(true)-$time)."s)\n";
}
Builds a SQL statement for adding a foreign key constraint to an existing table. The method will properly quote the table and column names.
addPrimaryKey() method (available since v1.1.13)
public void addPrimaryKey(string $name, string $table, string|array $columns) | ||
$name | string | name of the primary key constraint to add |
$table | string | name of the table to add primary key to |
$columns | string|array | comma separated string or array of columns that the primary key will consist of. Array value can be passed since 1.1.14. |
public function addPrimaryKey($name,$table,$columns)
{
echo " > alter table $table add constraint $name primary key (".(is_array($columns) ? implode(',', $columns) : $columns).") ...";
$time=microtime(true);
$this->getDbConnection()->createCommand()->addPrimaryKey($name,$table,$columns);
echo " done (time: ".sprintf('%.3f', microtime(true)-$time)."s)\n";
}
Builds and executes a SQL statement for creating a primary key, supports composite primary keys.
alterColumn() method
public void alterColumn(string $table, string $column, string $type) | ||
$table | string | the table whose column is to be changed. The table name will be properly quoted by the method. |
$column | string | the name of the column to be changed. The name will be properly quoted by the method. |
$type | string | the new column type. The getColumnType method will be invoked to convert abstract column type (if any) into the physical one. Anything that is not recognized as abstract type will be kept in the generated SQL. For example, 'string' will be turned into 'varchar(255)', while 'string not null' will become 'varchar(255) not null'. |
public function alterColumn($table, $column, $type)
{
echo " > alter column $column in table $table to $type ...";
$time=microtime(true);
$this->getDbConnection()->createCommand()->alterColumn($table, $column, $type);
echo " done (time: ".sprintf('%.3f', microtime(true)-$time)."s)\n";
}
Builds and executes a SQL statement for changing the definition of a column.
createIndex() method
public void createIndex(string $name, string $table, string|array $columns, boolean $unique=false) | ||
$name | string | the name of the index. The name will be properly quoted by the method. |
$table | string | the table that the new index will be created for. The table name will be properly quoted by the method. |
$columns | string|array | the column(s) that should be included in the index. If there are multiple columns, please separate them by commas or pass as an array of column names. Each column name will be properly quoted by the method, unless a parenthesis is found in the name. |
$unique | boolean | whether to add UNIQUE constraint on the created index. |
public function createIndex($name, $table, $columns, $unique=false)
{
echo " > create".($unique ? ' unique':'')." index $name on $table (".(is_array($columns) ? implode(',', $columns) : $columns).") ...";
$time=microtime(true);
$this->getDbConnection()->createCommand()->createIndex($name, $table, $columns, $unique);
echo " done (time: ".sprintf('%.3f', microtime(true)-$time)."s)\n";
}
Builds and executes a SQL statement for creating a new index.
createTable() method
public void createTable(string $table, array $columns, string $options=NULL) | ||
$table | string | the name of the table to be created. The name will be properly quoted by the method. |
$columns | array | the columns (name=>definition) in the new table. |
$options | string | additional SQL fragment that will be appended to the generated SQL. |
public function createTable($table, $columns, $options=null)
{
echo " > create table $table ...";
$time=microtime(true);
$this->getDbConnection()->createCommand()->createTable($table, $columns, $options);
echo " done (time: ".sprintf('%.3f', microtime(true)-$time)."s)\n";
}
Builds and executes 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 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.
delete() method
public void delete(string $table, mixed $conditions='', array $params=array ( )) | ||
$table | string | the table where the data will be deleted from. |
$conditions | mixed | the conditions that will be put in the WHERE part. Please refer to CDbCommand::where on how to specify conditions. |
$params | array | the parameters to be bound to the query. |
public function delete($table, $conditions='', $params=array())
{
echo " > delete from $table ...";
$time=microtime(true);
$this->getDbConnection()->createCommand()->delete($table, $conditions, $params);
echo " done (time: ".sprintf('%.3f', microtime(true)-$time)."s)\n";
}
Creates and executes a DELETE SQL statement.
down() method
public boolean down() | ||
{return} | boolean | Returning false means, the migration will not be applied. |
public function down()
{
$transaction=$this->getDbConnection()->beginTransaction();
try
{
if($this->safeDown()===false)
{
$transaction->rollback();
return false;
}
$transaction->commit();
}
catch(Exception $e)
{
echo "Exception: ".$e->getMessage().' ('.$e->getFile().':'.$e->getLine().")\n";
echo $e->getTraceAsString()."\n";
$transaction->rollback();
return false;
}
}
This method contains the logic to be executed when removing this migration. Child classes may override this method if the corresponding migrations can be removed.
dropColumn() method
public void dropColumn(string $table, string $column) | ||
$table | string | the table whose column is to be dropped. The name will be properly quoted by the method. |
$column | string | the name of the column to be dropped. The name will be properly quoted by the method. |
public function dropColumn($table, $column)
{
echo " > drop column $column from table $table ...";
$time=microtime(true);
$this->getDbConnection()->createCommand()->dropColumn($table, $column);
echo " done (time: ".sprintf('%.3f', microtime(true)-$time)."s)\n";
}
Builds and executes a SQL statement for dropping a DB column.
dropForeignKey() method
public void dropForeignKey(string $name, string $table) | ||
$name | string | the name of the foreign key constraint to be dropped. The name will be properly quoted by the method. |
$table | string | the table whose foreign is to be dropped. The name will be properly quoted by the method. |
public function dropForeignKey($name, $table)
{
echo " > drop foreign key $name from table $table ...";
$time=microtime(true);
$this->getDbConnection()->createCommand()->dropForeignKey($name, $table);
echo " done (time: ".sprintf('%.3f', microtime(true)-$time)."s)\n";
}
Builds a SQL statement for dropping a foreign key constraint.
dropIndex() method
public void dropIndex(string $name, string $table) | ||
$name | string | the name of the index to be dropped. The name will be properly quoted by the method. |
$table | string | the table whose index is to be dropped. The name will be properly quoted by the method. |
public function dropIndex($name, $table)
{
echo " > drop index $name ...";
$time=microtime(true);
$this->getDbConnection()->createCommand()->dropIndex($name, $table);
echo " done (time: ".sprintf('%.3f', microtime(true)-$time)."s)\n";
}
Builds and executes a SQL statement for dropping an index.
dropPrimaryKey() method (available since v1.1.13)
public void dropPrimaryKey(string $name, string $table) | ||
$name | string | name of the constraint to remove |
$table | string | name of the table to remove primary key from |
public function dropPrimaryKey($name,$table)
{
echo " > alter table $table drop primary key $name ...";
$time=microtime(true);
$this->getDbConnection()->createCommand()->dropPrimaryKey($name,$table);
echo " done (time: ".sprintf('%.3f', microtime(true)-$time)."s)\n";
}
Builds and executes a SQL statement for removing a primary key, supports composite primary keys.
dropTable() method
public void dropTable(string $table) | ||
$table | string | the table to be dropped. The name will be properly quoted by the method. |
public function dropTable($table)
{
echo " > drop table $table ...";
$time=microtime(true);
$this->getDbConnection()->createCommand()->dropTable($table);
echo " done (time: ".sprintf('%.3f', microtime(true)-$time)."s)\n";
}
Builds and executes a SQL statement for dropping a DB table.
execute() method (available since v1.1.7)
public void execute(string $sql, array $params=array ( )) | ||
$sql | string | the SQL statement to be executed |
$params | array | input parameters (name=>value) for the SQL execution. See CDbCommand::execute for more details. |
public function execute($sql, $params=array())
{
echo " > execute SQL: $sql ...";
$time=microtime(true);
$this->getDbConnection()->createCommand($sql)->execute($params);
echo " done (time: ".sprintf('%.3f', microtime(true)-$time)."s)\n";
}
Executes a SQL statement. This method executes the specified SQL statement using dbConnection.
getDbConnection() method
public CDbConnection getDbConnection() | ||
{return} | CDbConnection | the currently active database connection |
public function getDbConnection()
{
if($this->_db===null)
{
$this->_db=Yii::app()->getComponent('db');
if(!$this->_db instanceof CDbConnection)
throw new CException(Yii::t('yii', 'The "db" application component must be configured to be a CDbConnection object.'));
}
return $this->_db;
}
Returns the currently active database connection. By default, the 'db' application component will be returned and activated. You can call setDbConnection to switch to a different database connection. Methods such as insert, createTable will use this database connection to perform DB queries.
insert() method
public void insert(string $table, array $columns) | ||
$table | string | the table that new rows will be inserted into. |
$columns | array | the column data (name=>value) to be inserted into the table. |
public function insert($table, $columns)
{
echo " > insert into $table ...";
$time=microtime(true);
$this->getDbConnection()->createCommand()->insert($table, $columns);
echo " done (time: ".sprintf('%.3f', microtime(true)-$time)."s)\n";
}
Creates and executes an INSERT SQL statement. The method will properly escape the column names, and bind the values to be inserted.
insertMultiple() method (available since v1.1.16)
public void insertMultiple(string $table, array $data) | ||
$table | string | the table that new rows will be inserted into. |
$data | array | an array of various column data (name=>value) to be inserted into the table. |
public function insertMultiple($table, $data)
{
echo " > insert into $table ...";
$time=microtime(true);
$builder=$this->getDbConnection()->getSchema()->getCommandBuilder();
$command=$builder->createMultipleInsertCommand($table,$data);
$command->execute();
echo " done (time: ".sprintf('%.3f', microtime(true)-$time)."s)\n";
}
Creates and executes an INSERT SQL statement with multiple data. The method will properly escape the column names, and bind the values to be inserted.
refreshTableSchema() method (available since v1.1.9)
public void refreshTableSchema(string $table) | ||
$table | string | name of the table to refresh |
public function refreshTableSchema($table)
{
echo " > refresh table $table schema cache ...";
$time=microtime(true);
$this->getDbConnection()->getSchema()->getTable($table,true);
echo " done (time: ".sprintf('%.3f', microtime(true)-$time)."s)\n";
}
Refreshed schema cache for a table
renameColumn() method
public void renameColumn(string $table, string $name, string $newName) | ||
$table | string | the table whose column is to be renamed. The name will be properly quoted by the method. |
$name | string | the old name of the column. The name will be properly quoted by the method. |
$newName | string | the new name of the column. The name will be properly quoted by the method. |
public function renameColumn($table, $name, $newName)
{
echo " > rename column $name in table $table to $newName ...";
$time=microtime(true);
$this->getDbConnection()->createCommand()->renameColumn($table, $name, $newName);
echo " done (time: ".sprintf('%.3f', microtime(true)-$time)."s)\n";
}
Builds and executes a SQL statement for renaming a column.
renameTable() method
public void renameTable(string $table, string $newName) | ||
$table | string | the table to be renamed. The name will be properly quoted by the method. |
$newName | string | the new table name. The name will be properly quoted by the method. |
public function renameTable($table, $newName)
{
echo " > rename table $table to $newName ...";
$time=microtime(true);
$this->getDbConnection()->createCommand()->renameTable($table, $newName);
echo " done (time: ".sprintf('%.3f', microtime(true)-$time)."s)\n";
}
Builds and executes a SQL statement for renaming a DB table.
safeDown() method (available since v1.1.7)
public boolean safeDown() | ||
{return} | boolean | Returning false means, the migration will not be applied and the transaction will be rolled back. |
This method contains the logic to be executed when removing this migration. This method differs from down in that the DB logic implemented here will be enclosed within a DB transaction. Child classes may implement this method instead of up if the DB logic needs to be within a transaction.
safeUp() method (available since v1.1.7)
public boolean safeUp() | ||
{return} | boolean | Returning false means, the migration will not be applied and the transaction will be rolled back. |
This method contains the logic to be executed when applying this migration. This method differs from up in that the DB logic implemented here will be enclosed within a DB transaction. Child classes may implement this method instead of up if the DB logic needs to be within a transaction.
setDbConnection() method
public void setDbConnection(CDbConnection $db) | ||
$db | CDbConnection | the database connection component |
public function setDbConnection($db)
{
$this->_db=$db;
}
Sets the currently active database connection. The database connection will be used by the methods such as insert, createTable.
truncateTable() method
public void truncateTable(string $table) | ||
$table | string | the table to be truncated. The name will be properly quoted by the method. |
public function truncateTable($table)
{
echo " > truncate table $table ...";
$time=microtime(true);
$this->getDbConnection()->createCommand()->truncateTable($table);
echo " done (time: ".sprintf('%.3f', microtime(true)-$time)."s)\n";
}
Builds and executes a SQL statement for truncating a DB table.
up() method
public boolean up() | ||
{return} | boolean | Returning false means, the migration will not be applied. |
public function up()
{
$transaction=$this->getDbConnection()->beginTransaction();
try
{
if($this->safeUp()===false)
{
$transaction->rollback();
return false;
}
$transaction->commit();
}
catch(Exception $e)
{
echo "Exception: ".$e->getMessage().' ('.$e->getFile().':'.$e->getLine().")\n";
echo $e->getTraceAsString()."\n";
$transaction->rollback();
return false;
}
}
This method contains the logic to be executed when applying this migration. Child classes may implement this method to provide actual migration logic.
update() method
public void update(string $table, array $columns, mixed $conditions='', array $params=array ( )) | ||
$table | string | the table to be updated. |
$columns | array | the column data (name=>value) to be updated. |
$conditions | mixed | the conditions that will be put in the WHERE part. Please refer to CDbCommand::where on how to specify conditions. |
$params | array | the parameters to be bound to the query. |
public function update($table, $columns, $conditions='', $params=array())
{
echo " > update $table ...";
$time=microtime(true);
$this->getDbConnection()->createCommand()->update($table, $columns, $conditions, $params);
echo " done (time: ".sprintf('%.3f', microtime(true)-$time)."s)\n";
}
Creates and executes an UPDATE SQL statement. The method will properly escape the column names and bind the values to be updated.
© 2008–2017 by Yii Software LLC
Licensed under the three clause BSD license.
http://www.yiiframework.com/doc/api/1.1/CDbMigration