COMMIT TRANSACTION (Transact-SQL)

APPLIES TO: yesSQL Server yesAzure SQL Database yesAzure SQL Data Warehouse yesParallel Data Warehouse

Marks the end of a successful implicit or explicit transaction. If @@TRANCOUNT is 1, COMMIT TRANSACTION makes all data modifications since the start of the transaction a permanent part of the database, frees the transaction's resources, and decrements @@TRANCOUNT to 0. When @@TRANCOUNT is greater than 1, COMMIT TRANSACTION decrements @@TRANCOUNT only by 1 and the transaction stays active.

Article link icon Transact-SQL Syntax Conventions

Syntax

-- Applies to SQL Server (starting with 2008) and Azure SQL Database
  
COMMIT [ { TRAN | TRANSACTION }  [ transaction_name | @tran_name_variable ] ] [ WITH ( DELAYED_DURABILITY = { OFF | ON } ) ]  
[ ; ]  
-- Applies to Azure SQL Data Warehouse and Parallel Data Warehouse Database
  
COMMIT [ TRAN | TRANSACTION ] 
[ ; ]  

Arguments

transaction_name
APPLIES TO: SQL Server and Azure SQL Database

Is ignored by the SQL Server Database Engine. transaction_name specifies a transaction name assigned by a previous BEGIN TRANSACTION. transaction_namemust conform to the rules for identifiers, but can't exceed 32 characters. transaction_name indicates to programmers which nested BEGIN TRANSACTION the COMMIT TRANSACTION is associated with.

*@tran_name_variable*
APPLIES TO: SQL Server and Azure SQL Database

Is the name of a user-defined variable containing a valid transaction name. The variable must be declared with a char, varchar, nchar, or nvarchar data type. If more than 32 characters are passed to the variable, only 32 characters will be used; the remaining characters are truncated.

DELAYED_DURABILITY
APPLIES TO: SQL Server and Azure SQL Database

Option that requests this transaction should be committed with delayed durability. The request is ignored if the database has been altered with DELAYED_DURABILITY = DISABLED or DELAYED_DURABILITY = FORCED. For more information, see Control Transaction Durability.

Remarks

It's the responsibility of the Transact-SQL programmer to issue COMMIT TRANSACTION only at a point when all data referenced by the transaction is logically correct.

If the transaction committed was a Transact-SQL distributed transaction, COMMIT TRANSACTION triggers MS DTC to use a two-phase commit protocol to commit all of the servers involved in the transaction. When a local transaction spans two or more databases on the same instance of the Database Engine, the instance uses an internal two-phase commit to commit all of the databases involved in the transaction.

When used in nested transactions, commits of the inner transactions don't free resources or make their modifications permanent. The data modifications are made permanent and resources freed only when the outer transaction is committed. Each COMMIT TRANSACTION issued when @@TRANCOUNT is greater than one simply decrements @@TRANCOUNT by 1. When @@TRANCOUNT is finally decremented to 0, the entire outer transaction is committed. Because transaction_name is ignored by the Database Engine, issuing a COMMIT TRANSACTION referencing the name of an outer transaction when there are outstanding inner transactions only decrements @@TRANCOUNT by 1.

Issuing a COMMIT TRANSACTION when @@TRANCOUNT is zero results in an error; there's no corresponding BEGIN TRANSACTION.

You can't roll back a transaction after a COMMIT TRANSACTION statement is issued because the data modifications have been made a permanent part of the database.

The Database Engine increments the transaction count within a statement only when the transaction count is 0 at the start of the statement.

Permissions

Requires membership in the public role.

Examples

A. Committing a transaction

APPLIES TO: SQL Server, Azure SQL Database, Azure SQL Data Warehouse, and Parallel Data Warehouse

The following example deletes a job candidate. It uses AdventureWorks.

BEGIN TRANSACTION;   
DELETE FROM HumanResources.JobCandidate  
    WHERE JobCandidateID = 13;   
COMMIT TRANSACTION;   

B. Committing a nested transaction

APPLIES TO: SQL Server and Azure SQL Database

The following example creates a table, generates three levels of nested transactions, and then commits the nested transaction. Although each COMMIT TRANSACTION statement has a transaction_name parameter, there's no relationship between the COMMIT TRANSACTION and BEGIN TRANSACTION statements. The transaction_name parameters help the programmer ensure that the correct number of commits are coded to decrement @@TRANCOUNT to 0 and so to commit the outer transaction.

IF OBJECT_ID(N'TestTran',N'U') IS NOT NULL  
    DROP TABLE TestTran;  
GO  
CREATE TABLE TestTran (Cola int PRIMARY KEY, Colb char(3));  
GO  
-- This statement sets @@TRANCOUNT to 1.  
BEGIN TRANSACTION OuterTran;  
  
PRINT N'Transaction count after BEGIN OuterTran = '  
    + CAST(@@TRANCOUNT AS nvarchar(10));  
 
INSERT INTO TestTran VALUES (1, 'aaa');  
 
-- This statement sets @@TRANCOUNT to 2.  
BEGIN TRANSACTION Inner1;  
 
PRINT N'Transaction count after BEGIN Inner1 = '  
    + CAST(@@TRANCOUNT AS nvarchar(10));  
  
INSERT INTO TestTran VALUES (2, 'bbb');  
  
-- This statement sets @@TRANCOUNT to 3.  
BEGIN TRANSACTION Inner2;  
  
PRINT N'Transaction count after BEGIN Inner2 = '  
    + CAST(@@TRANCOUNT AS nvarchar(10));  
  
INSERT INTO TestTran VALUES (3, 'ccc');  
  
-- This statement decrements @@TRANCOUNT to 2.  
-- Nothing is committed.  
COMMIT TRANSACTION Inner2;  
 
PRINT N'Transaction count after COMMIT Inner2 = '  
    + CAST(@@TRANCOUNT AS nvarchar(10));  
 
-- This statement decrements @@TRANCOUNT to 1.  
-- Nothing is committed.  
COMMIT TRANSACTION Inner1;  
 
PRINT N'Transaction count after COMMIT Inner1 = '  
    + CAST(@@TRANCOUNT AS nvarchar(10));  
  
-- This statement decrements @@TRANCOUNT to 0 and  
-- commits outer transaction OuterTran.  
COMMIT TRANSACTION OuterTran;  
  
PRINT N'Transaction count after COMMIT OuterTran = '  
    + CAST(@@TRANCOUNT AS nvarchar(10));  

See Also

BEGIN DISTRIBUTED TRANSACTION (Transact-SQL)
BEGIN TRANSACTION (Transact-SQL)
COMMIT WORK (Transact-SQL)
ROLLBACK TRANSACTION (Transact-SQL)
ROLLBACK WORK (Transact-SQL)
SAVE TRANSACTION (Transact-SQL)
@@TRANCOUNT (Transact-SQL)