COMMIT TRANSACTION (Transact-SQL)
Applies to:
SQL Server
Azure SQL Database
Azure SQL Managed Instance
Azure Synapse Analytics
Analytics Platform System (PDW)
Warehouse in Microsoft Fabric
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.
Transact-SQL syntax conventions
Syntax
Syntax for SQL Server and Azure SQL Database.
COMMIT [ { TRAN | TRANSACTION }
[ transaction_name | @tran_name_variable ] ]
[ WITH ( DELAYED_DURABILITY = { OFF | ON } ) ]
[ ; ]
Syntax for Synapse Data Warehouse in Microsoft Fabric, Azure Synapse Analytics, and Parallel Data Warehouse Database.
COMMIT [ TRAN | TRANSACTION ]
[ ; ]
Note
To view Transact-SQL syntax for SQL Server 2014 (12.x) and earlier versions, see Previous versions documentation.
Arguments
transaction_name
Applies to: SQL Server and Azure SQL Database
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
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 are used. The remaining characters are truncated.
WITH DELAYED_DURABILITY = { OFF | ON }
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 was 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 were 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
The Transact-SQL code samples in this article use the AdventureWorks2022
or AdventureWorksDW2022
sample database, which you can download from the Microsoft SQL Server Samples and Community Projects home page.
A. Commit a transaction
Applies to: SQL Server, Azure SQL Database, Azure Synapse Analytics, and Analytics Platform System (PDW)
The following example deletes a job candidate.
BEGIN TRANSACTION;
DELETE FROM HumanResources.JobCandidate
WHERE JobCandidateID = 13;
COMMIT TRANSACTION;
B. Commit 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));