SQL Server/T-SQL Tutorial/Transact SQL/Try catch
Содержание
Another TRY/CATCH
6> BEGIN TRY
7> SELECT 1/0 AS DivideByZero
8> SELECT 1 AS NoError
9> END TRY
10> BEGIN CATCH
11> SELECT "Exception Caught!" AS CatchMessage
12> END CATCH
13> GO
DivideByZero
------------
(0 rows affected)
CatchMessage
-----------------
Exception Caught!
(1 rows affected)
1>
2>
Applying TRY...CATCH Error Handling Without Recoding a Stored Procedure
5> CREATE PROCEDURE usp_SEL_DivideByZero
6> AS
7> SELECT 1/0
8> GO
1>
2> BEGIN TRY
3> EXEC dbo.usp_SEL_DivideByZero
4> END TRY
5> BEGIN CATCH
6> SELECT ERROR_NUMBER() ErrorNBR, ERROR_SEVERITY() Severity,
7> ERROR_LINE () ErrorLine, ERROR_MESSAGE() Msg
8> PRINT "This stored procedure did not execute properly."
9> END CATCH
10> GO
-----------
(0 rows affected)
ErrorNBR Severity ErrorLine Msg
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8134 16 5 Divide by zero error encountered.
(1 rows affected)
This stored procedure did not execute properly.
1>
Basic TRY/CATCH
5> BEGIN TRY
6> SELECT 1/0 AS DivideByZero
7> END TRY
8> BEGIN CATCH
9> SELECT "Exception Caught!" AS CatchMessage
10> END CATCH
11> GO
DivideByZero
------------
(0 rows affected)
CatchMessage
-----------------
Exception Caught!
(1 rows affected)
1>
Error Handling in SQL Server 2005
4>
5> CREATE PROCEDURE spDeleteProduct @Productid int
6> AS
7> BEGIN TRY
8> BEGIN TRANSACTION
9> DELETE Product WHERE ProductID = @ID
10> COMMIT TRANSACTION
11> END TRY
12> BEGIN CATCH
13> DECLARE @Err AS int
14> DECLARE @Msg AS varchar(max)
15> SET @Err = @@Error
16> SET @Msg = Error_Message()
17> ROLLBACK TRANSACTION
18> INSERT ErrorTable
19> VALUES (@err, @msg)
20> END CATCH
21> GO
1>
2>
3> drop PROCEDURE spProduct_Delete;
4> GO
1>
2>
3> drop table Product;
4> GO
Error Handling with TRY...CATCH
3>
4> CREATE TABLE employee(
5> id INTEGER NOT NULL PRIMARY KEY,
6> first_name VARCHAR(10),
7> last_name VARCHAR(10),
8> salary DECIMAL(10,2),
9> start_Date DATETIME,
10> region VARCHAR(10),
11> city VARCHAR(20),
12> managerid INTEGER
13> );
14> GO
1> INSERT INTO employee VALUES (1, "Jason" , "Martin", 5890,"2005-03-22","North","Vancouver",3);
2> GO
(1 rows affected)
1> INSERT INTO employee VALUES (2, "Alison", "Mathews",4789,"2003-07-21","South","Utown",4);
2> GO
(1 rows affected)
1> INSERT INTO employee VALUES (3, "James" , "Smith", 6678,"2001-12-01","North","Paris",5);
2> GO
(1 rows affected)
1> INSERT INTO employee VALUES (4, "Celia" , "Rice", 5567,"2006-03-03","South","London",6);
2> GO
(1 rows affected)
1> INSERT INTO employee VALUES (5, "Robert", "Black", 4467,"2004-07-02","East","Newton",7);
2> GO
(1 rows affected)
1> INSERT INTO employee VALUES (6, "Linda" , "Green" , 6456,"2002-05-19","East","Calgary",8);
2> GO
(1 rows affected)
1> INSERT INTO employee VALUES (7, "David" , "Larry", 5345,"2008-03-18","West","New York",9);
2> GO
(1 rows affected)
1> INSERT INTO employee VALUES (8, "James" , "Cat", 4234,"2007-07-17","West","Regina",9);
2> GO
(1 rows affected)
1> INSERT INTO employee VALUES (9, "Joan" , "Act", 6123,"2001-04-16","North","Toronto",10);
2> GO
(1 rows affected)
1>
2> select * from employee;
3> GO
id first_name last_name salary start_Date region city managerid
----------- ---------- ---------- ------------ ----------------------- ---------- -------------------- -----------
1 Jason Martin 5890.00 2005-03-22 00:00:00.000 North Vancouver 3
2 Alison Mathews 4789.00 2003-07-21 00:00:00.000 South Utown 4
3 James Smith 6678.00 2001-12-01 00:00:00.000 North Paris 5
4 Celia Rice 5567.00 2006-03-03 00:00:00.000 South London 6
5 Robert Black 4467.00 2004-07-02 00:00:00.000 East Newton 7
6 Linda Green 6456.00 2002-05-19 00:00:00.000 East Calgary 8
7 David Larry 5345.00 2008-03-18 00:00:00.000 West New York 9
8 James Cat 4234.00 2007-07-17 00:00:00.000 West Regina 9
9 Joan Act 6123.00 2001-04-16 00:00:00.000 North Toronto 10
(9 rows affected)
1>
2>
3>
4> BEGIN TRY
5> BEGIN TRAN
6> INSERT employee(ID, first_Name)VALUES(1,"T")
7> INSERT employee(ID, first_Name)VALUES(11,"F")
8> COMMIT TRANSACTION
9> END TRY
10> BEGIN CATCH
11> SELECT ERROR_NUMBER() ErrorNBR, ERROR_SEVERITY() Severity,
12> ERROR_LINE () ErrorLine, ERROR_MESSAGE() Msg
13> ROLLBACK TRANSACTION
14> END CATCH
15>
16>
17>
18> drop table employee;
19> GO
ErrorNBR Severity ErrorLine Msg
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2627 14 6 Violation of PRIMARY KEY constraint "PK__employee__41248F15". Cannot insert duplicat
e key in object "dbo.employee".
(1 rows affected)
1>
Nesting TRY...CATCH Calls
4>
5> CREATE TABLE employee(
6> id INTEGER,
7> first_name VARCHAR(10),
8> last_name VARCHAR(10),
9> salary DECIMAL(10,2),
10> start_Date DATETIME,
11> region VARCHAR(10),
12> city VARCHAR(20),
13> managerid INTEGER
14> );
15> GO
1> INSERT INTO employee VALUES (1, "Jason" , "Martin", 5890,"2005-03-22","North","Vancouver",3);
2> GO
(1 rows affected)
1> INSERT INTO employee VALUES (2, "Alison", "Mathews",4789,"2003-07-21","South","Utown",4);
2> GO
(1 rows affected)
1> INSERT INTO employee VALUES (3, "James" , "Smith", 6678,"2001-12-01","North","Paris",5);
2> GO
(1 rows affected)
1> INSERT INTO employee VALUES (4, "Celia" , "Rice", 5567,"2006-03-03","South","London",6);
2> GO
(1 rows affected)
1> INSERT INTO employee VALUES (5, "Robert", "Black", 4467,"2004-07-02","East","Newton",7);
2> GO
(1 rows affected)
1> INSERT INTO employee VALUES (6, "Linda" , "Green" , 6456,"2002-05-19","East","Calgary",8);
2> GO
(1 rows affected)
1> INSERT INTO employee VALUES (7, "David" , "Larry", 5345,"2008-03-18","West","New York",9);
2> GO
(1 rows affected)
1> INSERT INTO employee VALUES (8, "James" , "Cat", 4234,"2007-07-17","West","Regina",9);
2> GO
(1 rows affected)
1> INSERT INTO employee VALUES (9, "Joan" , "Act", 6123,"2001-04-16","North","Toronto",10);
2> GO
(1 rows affected)
1>
2> select * from employee;
3> GO
id first_name last_name salary start_Date region city managerid
----------- ---------- ---------- ------------ ----------------------- ---------- -------------------- -----------
1 Jason Martin 5890.00 2005-03-22 00:00:00.000 North Vancouver 3
2 Alison Mathews 4789.00 2003-07-21 00:00:00.000 South Utown 4
3 James Smith 6678.00 2001-12-01 00:00:00.000 North Paris 5
4 Celia Rice 5567.00 2006-03-03 00:00:00.000 South London 6
5 Robert Black 4467.00 2004-07-02 00:00:00.000 East Newton 7
6 Linda Green 6456.00 2002-05-19 00:00:00.000 East Calgary 8
7 David Larry 5345.00 2008-03-18 00:00:00.000 West New York 9
8 James Cat 4234.00 2007-07-17 00:00:00.000 West Regina 9
9 Joan Act 6123.00 2001-04-16 00:00:00.000 North Toronto 10
(9 rows affected)
1>
2>
3> CREATE PROCEDURE dbo.usp_employee @Name nvarchar(50),@GroupName nvarchar(50)
4> AS
5> BEGIN TRY
6> INSERT employee (first_Name, region)VALUES (@Name, @GroupName)
7> END TRY
8> BEGIN CATCH
9> BEGIN TRY
10> PRINT "The first department attempt failed."
11> INSERT employee(first_Name, region)VALUES ("Misc", @GroupName)
12> END TRY
13> BEGIN CATCH
14> PRINT "A Misc department for that group already exists."
15> END CATCH
16> END CATCH
17> GO
1>
2> EXEC dbo.usp_employee "E", "North"
3> GO
(1 rows affected)
1>
2> EXEC dbo.usp_employee "G", "South"
3> GO
(1 rows affected)
1>
2> drop table employee;
3> GO
1>
try...catch Demo
7> CREATE TABLE SomeData
8> (
9> SomeColumn INT
10> )
11> GO
1>
2> BEGIN TRANSACTION
3>
4> BEGIN TRY
5> --Throw an exception on insert
6> INSERT SomeData VALUES (CONVERT(INT, "abc"))
7> END TRY
8> BEGIN CATCH
9> --Try to commit...
10> COMMIT TRANSACTION
11> END CATCH
12> GO
Msg 3930, Level 16, State 1, Server J\SQLEXPRESS, Line 10
The current transaction cannot be committed and cannot support operations that write to the log file. Roll back the transaction.
1>
2>
3> drop table SomeData;
4> GO