SQL Server/T-SQL Tutorial/Transact SQL/Goto — различия между версиями

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Текущая версия на 10:22, 26 мая 2010

Goto statement

2>
3> CREATE TABLE a (
4> a char(1) primary key)
5>
6> CREATE TABLE b (
7> b char(1) references a)
8>
9> CREATE TABLE c (
10> c char(1))
11> GO
1>
2> CREATE PROC test as
3> BEGIN TRANSACTION
4> INSERT c VALUES ("X")
5>     IF (@@ERROR <> 0) GOTO on_error
6> INSERT b VALUES ("X")  -- Fails reference
7>     IF (@@ERROR <> 0) GOTO on_error
8> COMMIT TRANSACTION
9> RETURN(0)
10>
11> on_error:
12> ROLLBACK TRANSACTION
13> RETURN(1)
14>
15> GO


IF @@ERROR <> 0 GOTO TRAN_ABORT

3> IF EXISTS (SELECT * FROM sysobjects WHERE name="show_error"
4>     AND type="U")
5>     DROP TABLE show_error
6> GO
1>
2> CREATE TABLE show_error
3> (
4> col1    smallint NOT NULL PRIMARY KEY,
5> col2    smallint NOT NULL
6> )
7> GO
1>
2> BEGIN TRANSACTION
3> INSERT show_error VALUES (1, 1)
4> IF @@ERROR <> 0 GOTO TRAN_ABORT
5> INSERT show_error VALUES (1, 2)
6> if @@ERROR <> 0 GOTO TRAN_ABORT
7> INSERT show_error VALUES (2, 2)
8> if @@ERROR <> 0 GOTO TRAN_ABORT
9> COMMIT TRANSACTION
10> GOTO FINISH
11>
12> TRAN_ABORT:
13> ROLLBACK TRANSACTION
14>
15> FINISH:
16> GO
(1 rows affected)
Msg 2627, Level 14, State 1, Server J\SQLEXPRESS, Line 5
Violation of PRIMARY KEY constraint "PK__show_error__762D5431". Cannot insert duplicate key in object "dbo.show_error".
The statement has been terminated.
1>
2> SELECT * FROM show_error
3> GO
col1   col2
------ ------
(0 rows affected)
1>
2> drop table show_error;
3> GO


Using GOTO

GOTO is used to jump to a label in your Transact-SQL batch. 
The syntax is:
GOTO label
label definition: code