HumHub Documentation (unofficial)

Transaction extends BaseObject
in package

Transaction represents a DB transaction.

It is usually created by calling [[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.

Tags
author

Qiang Xue qiang.xue@gmail.com

since
2.0

Table of Contents

Constants

READ_COMMITTED  = 'READ COMMITTED'
A constant representing the transaction isolation level `READ COMMITTED`.
READ_UNCOMMITTED  = 'READ UNCOMMITTED'
A constant representing the transaction isolation level `READ UNCOMMITTED`.
REPEATABLE_READ  = 'REPEATABLE READ'
A constant representing the transaction isolation level `REPEATABLE READ`.
SERIALIZABLE  = 'SERIALIZABLE'
A constant representing the transaction isolation level `SERIALIZABLE`.

Properties

$db  : Connection
$isActive  : bool
$isolationLevel  : string
$level  : int
$_level  : int

Methods

__call()  : mixed
Calls the named method which is not a class method.
__construct()  : mixed
Constructor.
__get()  : mixed
Returns the value of an object property.
__isset()  : bool
Checks if a property is set, i.e. defined and not null.
__set()  : mixed
Sets value of an object property.
__unset()  : mixed
Sets an object property to null.
begin()  : mixed
Begins a transaction.
canGetProperty()  : bool
Returns a value indicating whether a property can be read.
canSetProperty()  : bool
Returns a value indicating whether a property can be set.
className()  : string
Returns the fully qualified name of this class.
commit()  : mixed
Commits a transaction.
getIsActive()  : bool
Returns a value indicating whether this transaction is active.
getLevel()  : int
hasMethod()  : bool
Returns a value indicating whether a method is defined.
hasProperty()  : bool
Returns a value indicating whether a property is defined.
init()  : mixed
Initializes the object.
rollBack()  : mixed
Rolls back a transaction.
setIsolationLevel()  : mixed
Sets the transaction isolation level for this transaction.

Constants

Properties

$isActive read-only

public bool $isActive

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

$isolationLevel write-only

public string $isolationLevel

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.

$level read-only

public int $level

The current nesting level of the transaction.

$_level

private int $_level = 0

the nesting level of the transaction. 0 means the outermost level.

Methods

__call()

Calls the named method which is not a class method.

public __call(string $name, array<string|int, mixed> $params) : mixed

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.

Parameters
$name : string

the method name

$params : array<string|int, mixed>

method parameters

Tags
throws
UnknownMethodException

when calling unknown method

Return values
mixed —

the method return value

__construct()

Constructor.

public __construct([array<string|int, mixed> $config = [] ]) : mixed

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.
Parameters
$config : array<string|int, mixed> = []

name-value pairs that will be used to initialize the object properties

__get()

Returns the value of an object property.

public __get(string $name) : mixed

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

Parameters
$name : string

the property name

Tags
throws
UnknownPropertyException

if the property is not defined

throws
InvalidCallException

if the property is write-only

see
__set()
Return values
mixed —

the property value

__isset()

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

public __isset(string $name) : bool

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.

Parameters
$name : string

the property name or the event name

Tags
see
https://www.php.net/manual/en/function.isset.php
Return values
bool —

whether the named property is set (not null).

__set()

Sets value of an object property.

public __set(string $name, mixed $value) : mixed

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

Parameters
$name : string

the property name or the event name

$value : mixed

the property value

Tags
throws
UnknownPropertyException

if the property is not defined

throws
InvalidCallException

if the property is read-only

see
__get()

__unset()

Sets an object property to null.

public __unset(string $name) : mixed

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.

Parameters
$name : string

the property name

Tags
throws
InvalidCallException

if the property is read only.

see
https://www.php.net/manual/en/function.unset.php

begin()

Begins a transaction.

public begin([string|null $isolationLevel = null ]) : mixed
Parameters
$isolationLevel : string|null = 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.

Tags
throws
InvalidConfigException

if [[db]] is null

throws
NotSupportedException

if the DBMS does not support nested transactions

throws
Exception

if DB connection fails

canGetProperty()

Returns a value indicating whether a property can be read.

public canGetProperty(string $name[, bool $checkVars = true ]) : bool

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);
Parameters
$name : string

the property name

$checkVars : bool = true

whether to treat member variables as properties

Tags
see
canSetProperty()
Return values
bool —

whether the property can be read

canSetProperty()

Returns a value indicating whether a property can be set.

public canSetProperty(string $name[, bool $checkVars = true ]) : bool

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);
Parameters
$name : string

the property name

$checkVars : bool = true

whether to treat member variables as properties

Tags
see
canGetProperty()
Return values
bool —

whether the property can be written

className()

Returns the fully qualified name of this class.

public static className() : string
Tags
deprecated

since 2.0.14. On PHP >=5.5, use ::class instead.

Return values
string —

the fully qualified name of this class.

commit()

Commits a transaction.

public commit() : mixed
Tags
throws
Exception

if the transaction is not active

getIsActive()

Returns a value indicating whether this transaction is active.

public getIsActive() : bool
Return values
bool —

whether this transaction is active. Only an active transaction can [[commit()]] or [[rollBack()]].

getLevel()

public getLevel() : int
Tags
since
2.0.8
Return values
int —

The current nesting level of the transaction.

hasMethod()

Returns a value indicating whether a method is defined.

public hasMethod(string $name) : bool

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

Parameters
$name : string

the method name

Return values
bool —

whether the method is defined

hasProperty()

Returns a value indicating whether a property is defined.

public hasProperty(string $name[, bool $checkVars = true ]) : bool

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);
Parameters
$name : string

the property name

$checkVars : bool = true

whether to treat member variables as properties

Tags
see
canGetProperty()
see
canSetProperty()
Return values
bool —

whether the property is defined

init()

Initializes the object.

public init() : mixed

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

rollBack()

Rolls back a transaction.

public rollBack() : mixed

setIsolationLevel()

Sets the transaction isolation level for this transaction.

public setIsolationLevel(string $level) : mixed

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()]].

Parameters
$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.

Tags
throws
Exception

if the transaction is not active

see
https://en.wikipedia.org/wiki/Isolation_%28database_systems%29#Isolation_levels 

        

        
    




    

    

                                

                

                                
    

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