# Class yii\db\Transaction

Inheritance | yii\db\Transaction » yii\base\BaseObject
Implements | yii\base\Configurable
Available since version | 2.0
Source Code | https://github.com/yiisoft/yii2/blob/master/framework/db/Transaction.php

Transaction represents a DB transaction.

It is usually created by calling yii\db\Connection::beginTransaction().

The following code is a typical example of using transactions (note that some DBMS may not support transactions):

    $transaction = $connection->beginTransaction();
    try {
        $connection->createCommand($sql1)->execute();
        $connection->createCommand($sql2)->execute();
        //.... other SQL executions
        $transaction->commit();
    } catch (\Exception $e) {
        $transaction->rollBack();
        throw $e;
    } catch (\Throwable $e) {
        $transaction->rollBack();
        throw $e;
    }

> Note: in the above code we have two catch-blocks for compatibility with PHP 5.x and PHP 7.x. `\Exception` implements the `\Throwable` interface since PHP 7.0, so you can skip the part with `\Exception` if your app uses only PHP 7.0 and higher.

## Public Properties

Hide inherited properties

Property | Type | Description | Defined By
--- | --- | --- | ---
$db | yii\db\Connection | The database connection that this transaction is associated with. | yii\db\Transaction
$isActive | boolean | Whether this transaction is active. | yii\db\Transaction
$isolationLevel | string | The transaction isolation level to use for this transaction. | yii\db\Transaction
$level | integer | The current nesting level of the transaction. | yii\db\Transaction

## Public Methods

Hide inherited methods

Method | Description | Defined By
--- | --- | ---
__call() | Calls the named method which is not a class method. | yii\base\BaseObject
__construct() | Constructor. | yii\base\BaseObject
__get() | Returns the value of an object property. | yii\base\BaseObject
__isset() | Checks if a property is set, i.e. defined and not null. | yii\base\BaseObject
__set() | Sets value of an object property. | yii\base\BaseObject
__unset() | Sets an object property to null. | yii\base\BaseObject
begin() | Begins a transaction. | yii\db\Transaction
canGetProperty() | Returns a value indicating whether a property can be read. | yii\base\BaseObject
canSetProperty() | Returns a value indicating whether a property can be set. | yii\base\BaseObject
className() | Returns the fully qualified name of this class. | yii\base\BaseObject
commit() | Commits a transaction. | yii\db\Transaction
getIsActive() | Returns a value indicating whether this transaction is active. | yii\db\Transaction
getLevel() |  | yii\db\Transaction
hasMethod() | Returns a value indicating whether a method is defined. | yii\base\BaseObject
hasProperty() | Returns a value indicating whether a property is defined. | yii\base\BaseObject
init() | Initializes the object. | yii\base\BaseObject
rollBack() | Rolls back a transaction. | yii\db\Transaction
setIsolationLevel() | Sets the transaction isolation level for this transaction. | yii\db\Transaction

## Constants

Hide inherited constants

Constant | Value | Description | Defined By
--- | --- | --- | ---
READ_COMMITTED | 'READ COMMITTED' | A constant representing the transaction isolation level `READ COMMITTED`. | yii\db\Transaction
READ_UNCOMMITTED | 'READ UNCOMMITTED' | A constant representing the transaction isolation level `READ UNCOMMITTED`. | yii\db\Transaction
REPEATABLE_READ | 'REPEATABLE READ' | A constant representing the transaction isolation level `REPEATABLE READ`. | yii\db\Transaction
SERIALIZABLE | 'SERIALIZABLE' | A constant representing the transaction isolation level `SERIALIZABLE`. | yii\db\Transaction

## Property Details

Hide inherited properties

$db public property

The database connection that this transaction is associated with.

public yii\db\Connection $db = null
$isActive public property

Whether this transaction is active. Only an active transaction can commit() or rollBack().

public boolean $isActive = null
$isolationLevel public property

The transaction isolation level to use for this transaction. This can be one of READ_UNCOMMITTED, READ_COMMITTED, REPEATABLE_READ and SERIALIZABLE but also a string containing DBMS specific syntax to be used after `SET TRANSACTION ISOLATION LEVEL`.

public string $isolationLevel = null
$level public property

The current nesting level of the transaction.

public integer $level = null

## Method Details

Hide inherited methods

__call() public method

Defined in: yii\base\BaseObject::__call()

Calls the named method which is not a class method.

Do not call this method directly as it is a PHP magic method that will be implicitly called when an unknown method is being invoked.

public mixed __call ( $name, $params )
$name | string | The method name
$params | array | Method parameters
return | mixed | The method return value
throws | yii\base\UnknownMethodException | when calling unknown method

Source code

                    public function __call($name, $params)
    {
        throw new UnknownMethodException('Calling unknown method: ' . get_class($this) . "::$name()");
    }

__construct() public method

Defined in: yii\base\BaseObject::__construct()

Constructor.

The default implementation does two things:

- Initializes the object with the given configuration `$config`.
- Call init().

If this method is overridden in a child class, it is recommended that

- the last parameter of the constructor is a configuration array, like `$config` here.
- call the parent implementation at the end of the constructor.

public void __construct ( $config = [] )
$config | array | Name-value pairs that will be used to initialize the object properties

Source code

                    public function __construct($config = [])
    {
        if (!empty($config)) {
            Yii::configure($this, $config);
        }
        $this->init();
    }

__get() public method

Defined in: yii\base\BaseObject::__get()

Returns the value of an object property.

Do not call this method directly as it is a PHP magic method that will be implicitly called when executing `$value = $object->property;`.

See also __set().

public mixed __get ( $name )
$name | string | The property name
return | mixed | The property value
throws | yii\base\UnknownPropertyException | if the property is not defined
throws | yii\base\InvalidCallException | if the property is write-only

Source code

                    public function __get($name)
    {
        $getter = 'get' . $name;
        if (method_exists($this, $getter)) {
            return $this->$getter();
        } elseif (method_exists($this, 'set' . $name)) {
            throw new InvalidCallException('Getting write-only property: ' . get_class($this) . '::' . $name);
        }
        throw new UnknownPropertyException('Getting unknown property: ' . get_class($this) . '::' . $name);
    }

__isset() public method

Defined in: yii\base\BaseObject::__isset()

Checks if a property is set, i.e. defined and not null.

Do not call this method directly as it is a PHP magic method that will be implicitly called when executing `isset($object->property)`.

Note that if the property is not defined, false will be returned.

See also https://www.php.net/manual/en/function.isset.php.

public boolean __isset ( $name )
$name | string | The property name or the event name
return | boolean | Whether the named property is set (not null).

Source code

                    public function __isset($name)
    {
        $getter = 'get' . $name;
        if (method_exists($this, $getter)) {
            return $this->$getter() !== null;
        }
        return false;
    }

__set() public method

Defined in: yii\base\BaseObject::__set()

Sets value of an object property.

Do not call this method directly as it is a PHP magic method that will be implicitly called when executing `$object->property = $value;`.

See also __get().

public void __set ( $name, $value )
$name | string | The property name or the event name
$value | mixed | The property value
throws | yii\base\UnknownPropertyException | if the property is not defined
throws | yii\base\InvalidCallException | if the property is read-only

Source code

                    public function __set($name, $value)
    {
        $setter = 'set' . $name;
        if (method_exists($this, $setter)) {
            $this->$setter($value);
        } elseif (method_exists($this, 'get' . $name)) {
            throw new InvalidCallException('Setting read-only property: ' . get_class($this) . '::' . $name);
        } else {
            throw new UnknownPropertyException('Setting unknown property: ' . get_class($this) . '::' . $name);
        }
    }

__unset() public method

Defined in: yii\base\BaseObject::__unset()

Sets an object property to null.

Do not call this method directly as it is a PHP magic method that will be implicitly called when executing `unset($object->property)`.

Note that if the property is not defined, this method will do nothing. If the property is read-only, it will throw an exception.

See also https://www.php.net/manual/en/function.unset.php.

public void __unset ( $name )
$name | string | The property name
throws | yii\base\InvalidCallException | if the property is read only.

Source code

                    public function __unset($name)
    {
        $setter = 'set' . $name;
        if (method_exists($this, $setter)) {
            $this->$setter(null);
        } elseif (method_exists($this, 'get' . $name)) {
            throw new InvalidCallException('Unsetting read-only property: ' . get_class($this) . '::' . $name);
        }
    }

begin() public method

Begins a transaction.

public void begin ( $isolationLevel = null )

$isolationLevel

string|null

The isolation level to use for this transaction. This can be one of READ_UNCOMMITTED, READ_COMMITTED, REPEATABLE_READ and SERIALIZABLE but also a string containing DBMS specific syntax to be used after `SET TRANSACTION ISOLATION LEVEL`. If not specified (`null`) the isolation level will not be set explicitly and the DBMS default will be used.

> Note: This setting does not work for PostgreSQL, where setting the isolation level before the transaction has no effect. You have to call setIsolationLevel() in this case after the transaction has started.

> Note: Some DBMS allow setting of the isolation level only for the whole connection so subsequent transactions may get the same isolation level even if you did not specify any. When using this feature you may need to set the isolation level for all transactions explicitly to avoid conflicting settings. At the time of this writing affected DBMS are MSSQL and SQLite.

Starting from version 2.0.16, this method throws exception when beginning nested transaction and underlying DBMS does not support savepoints.

throws | yii\base\InvalidConfigException | if $db is `null`
throws | yii\base\NotSupportedException | if the DBMS does not support nested transactions
throws | yii\db\Exception | if DB connection fails

Source code

                    public function begin($isolationLevel = null)
    {
        if ($this->db === null) {
            throw new InvalidConfigException('Transaction::db must be set.');
        }
        $this->db->open();
        if ($this->_level === 0) {
            if ($isolationLevel !== null) {
                $this->db->getSchema()->setTransactionIsolationLevel($isolationLevel);
            }
            Yii::debug('Begin transaction' . ($isolationLevel ? ' with isolation level ' . $isolationLevel : ''), __METHOD__);
            $this->db->trigger(Connection::EVENT_BEGIN_TRANSACTION);
            $this->db->pdo->beginTransaction();
            $this->_level = 1;
            return;
        }
        $schema = $this->db->getSchema();
        if ($schema->supportsSavepoint()) {
            Yii::debug('Set savepoint ' . $this->_level, __METHOD__);
            // make sure the transaction wasn't autocommitted
            if ($this->db->pdo->inTransaction()) {
                $schema->createSavepoint('LEVEL' . $this->_level);
            }
        } else {
            Yii::info('Transaction not started: nested transaction not supported', __METHOD__);
            throw new NotSupportedException('Transaction not started: nested transaction not supported.');
        }
        $this->_level++;
    }

canGetProperty() public method

Defined in: yii\base\BaseObject::canGetProperty()

Returns a value indicating whether a property can be read.

A property is readable if:

- the class has a getter method associated with the specified name (in this case, property name is case-insensitive);
- the class has a member variable with the specified name (when `$checkVars` is true);

See also canSetProperty().

public boolean canGetProperty ( $name, $checkVars = true )
$name | string | The property name
$checkVars | boolean | Whether to treat member variables as properties
return | boolean | Whether the property can be read

Source code

                    public function canGetProperty($name, $checkVars = true)
    {
        return method_exists($this, 'get' . $name) || $checkVars && property_exists($this, $name);
    }

canSetProperty() public method

Defined in: yii\base\BaseObject::canSetProperty()

Returns a value indicating whether a property can be set.

A property is writable if:

- the class has a setter method associated with the specified name (in this case, property name is case-insensitive);
- the class has a member variable with the specified name (when `$checkVars` is true);

See also canGetProperty().

public boolean canSetProperty ( $name, $checkVars = true )
$name | string | The property name
$checkVars | boolean | Whether to treat member variables as properties
return | boolean | Whether the property can be written

Source code

                    public function canSetProperty($name, $checkVars = true)
    {
        return method_exists($this, 'set' . $name) || $checkVars && property_exists($this, $name);
    }

className() public static method
Deprecated since 2.0.14. On PHP >=5.5, use `::class` instead.

Defined in: yii\base\BaseObject::className()

Returns the fully qualified name of this class.

public static string className ( )
return | string | The fully qualified name of this class.

Source code

                    public static function className()
    {
        return get_called_class();
    }

commit() public method

Commits a transaction.

public void commit ( )
throws | yii\db\Exception | if the transaction is not active

Source code

                    public function commit()
    {
        if (!$this->getIsActive()) {
            throw new Exception('Failed to commit transaction: transaction was inactive.');
        }
        $this->_level--;
        if ($this->_level === 0) {
            Yii::debug('Commit transaction', __METHOD__);
            // make sure the transaction wasn't autocommitted
            if ($this->db->pdo->inTransaction()) {
                $this->db->pdo->commit();
            }
            $this->db->trigger(Connection::EVENT_COMMIT_TRANSACTION);
            return;
        }
        $schema = $this->db->getSchema();
        if ($schema->supportsSavepoint()) {
            Yii::debug('Release savepoint ' . $this->_level, __METHOD__);
            // make sure the transaction wasn't autocommitted
            if ($this->db->pdo->inTransaction()) {
                $schema->releaseSavepoint('LEVEL' . $this->_level);
            }
        } else {
            Yii::info('Transaction not committed: nested transaction not supported', __METHOD__);
        }
    }

getIsActive() public method

Returns a value indicating whether this transaction is active.

public boolean getIsActive ( )
return | boolean | Whether this transaction is active. Only an active transaction can commit() or rollBack().

Source code

                    public function getIsActive()
    {
        return $this->_level > 0 && $this->db && $this->db->isActive;
    }

getLevel() public method (available since version 2.0.8)

public integer getLevel ( )
return | integer | The current nesting level of the transaction.

Source code

                    public function getLevel()
    {
        return $this->_level;
    }

hasMethod() public method

Defined in: yii\base\BaseObject::hasMethod()

Returns a value indicating whether a method is defined.

The default implementation is a call to php function `method_exists()`. You may override this method when you implemented the php magic method `__call()`.

public boolean hasMethod ( $name )
$name | string | The method name
return | boolean | Whether the method is defined

Source code

                    public function hasMethod($name)
    {
        return method_exists($this, $name);
    }

hasProperty() public method

Defined in: yii\base\BaseObject::hasProperty()

Returns a value indicating whether a property is defined.

A property is defined if:

- the class has a getter or setter method associated with the specified name (in this case, property name is case-insensitive);
- the class has a member variable with the specified name (when `$checkVars` is true);

See also:

- canGetProperty()
- canSetProperty()

public boolean hasProperty ( $name, $checkVars = true )
$name | string | The property name
$checkVars | boolean | Whether to treat member variables as properties
return | boolean | Whether the property is defined

Source code

                    public function hasProperty($name, $checkVars = true)
    {
        return $this->canGetProperty($name, $checkVars) || $this->canSetProperty($name, false);
    }

init() public method

Defined in: yii\base\BaseObject::init()

Initializes the object.

This method is invoked at the end of the constructor after the object is initialized with the given configuration.

public void init ( )

Source code

                    public function init()
    {
    }

rollBack() public method

Rolls back a transaction.

public void rollBack ( )

Source code

                    public function rollBack()
    {
        if (!$this->getIsActive()) {
            // do nothing if transaction is not active: this could be the transaction is committed
            // but the event handler to "commitTransaction" throw an exception
            return;
        }
        $this->_level--;
        if ($this->_level === 0) {
            Yii::debug('Roll back transaction', __METHOD__);
            // make sure the transaction wasn't autocommitted
            if ($this->db->pdo->inTransaction()) {
                $this->db->pdo->rollBack();
            }
            $this->db->trigger(Connection::EVENT_ROLLBACK_TRANSACTION);
            return;
        }
        $schema = $this->db->getSchema();
        if ($schema->supportsSavepoint()) {
            Yii::debug('Roll back to savepoint ' . $this->_level, __METHOD__);
            // make sure the transaction wasn't autocommitted
            if ($this->db->pdo->inTransaction()) {
                $schema->rollBackSavepoint('LEVEL' . $this->_level);
            }
        } else {
            Yii::info('Transaction not rolled back: nested transaction not supported', __METHOD__);
        }
    }

setIsolationLevel() public method

Sets the transaction isolation level for this transaction.

This method can be used to set the isolation level while the transaction is already active. However this is not supported by all DBMS so you might rather specify the isolation level directly when calling begin().

See also https://en.wikipedia.org/wiki/Isolation_(database_systems)#Isolation_levels.

public void setIsolationLevel ( $level )
$level | string | The transaction isolation level to use for this transaction. This can be one of READ_UNCOMMITTED, READ_COMMITTED, REPEATABLE_READ and SERIALIZABLE but also a string containing DBMS specific syntax to be used after `SET TRANSACTION ISOLATION LEVEL`.
throws | yii\db\Exception | if the transaction is not active

Source code

                    public function setIsolationLevel($level)
    {
        if (!$this->getIsActive()) {
            throw new Exception('Failed to set isolation level: transaction was inactive.');
        }
        Yii::debug('Setting transaction isolation level to ' . $level, __METHOD__);
        $this->db->getSchema()->setTransactionIsolationLevel($level);
    }