ROLLBACK TRANSACTION 请求没有对应的 BEGIN TRANSACTION [英] ROLLBACK TRANSACTION request has no corresponding BEGIN TRANSACTION
问题描述
我已尝试将 COMMIT TRAN 置于 if else 循环中，但仍然出现此错误.
I've tried putting the COMMIT TRAN in a if else loop, and I'm still getting this error.
我必须为一个班级注册一名学生.如果注册后的座位数为负数，我必须将其反转并打印一条消息说不能注册.我已经放置了其他错误消息只是为了查看事务是如何工作的.
I have to enroll a student in a class. If the number of seats after enrollment falls in negative, I have to reverse it and print a message saying can't enroll. I have put other error messages just to see how transactions work.
CREATE PROCEDURE dbo.EnrollStudent ( @CourseID AS INTEGER,
@StudentID AS VARCHAR(20) ) AS
BEGIN
DECLARE @StatusID INTEGER
DECLARE @Status VARCHAR(50)
DECLARE @CurrentSeats INTEGER
DECLARE @ErrorCode INTEGER
SET @StatusID=0
IF EXISTS (SELECT 1
FROM dbo.CourseEnrollment
WHERE dbo.CourseEnrollment.CourseId=@CourseID AND dbo.CourseEnrollment.StudentId=@StudentID )
BEGIN
BEGIN TRAN Tr1
SET @StatusID = 1
SELECT @ErrorCode=@@ERROR
IF (@ErrorCode<>0) GOTO OTHERPROBLEM
ELSE
COMMIT TRAN Tr1
END
IF EXISTS ( SELECT 1
FROM dbo.CourseEnrollment
FULL OUTER JOIN dbo.Courses
ON dbo.Courses.CourseId=@CourseID
WHERE dbo.CourseEnrollment.StudentId<>@StudentID AND dbo.Courses.Faculty IS NULL )
BEGIN
BEGIN TRAN Tr2
SET @StatusID=2
SELECT @ErrorCode=@@ERROR
IF (@ErrorCode<>0) GOTO OTHERPROBLEM2
ELSE
COMMIT TRAN Tr2
END
IF @StatusID=0
BEGIN
IF EXISTS ( SELECT 1
FROM dbo.Courses
WHERE dbo.Courses.CourseId=@CourseID AND dbo.Courses.Faculty IS NOT NULL )
BEGIN
BEGIN TRAN Tr3
SET @StatusID=3
BEGIN TRAN InsertingValues
INSERT INTO dbo.CourseEnrollment (dbo.CourseEnrollment.StudentId,dbo.CourseEnrollment.CourseId)
VALUES (@StudentID,@CourseID);
SELECT @ErrorCode=@@ERROR
IF (@ErrorCode<>0) GOTO InsertProblem
ELSE
COMMIT TRAN InsertingValues
BEGIN TRAN UpdateCourses
UPDATE dbo.Courses
SET OpenSeats = OpenSeats-1
WHERE dbo.Courses.CourseId = @CourseID
SELECT @ErrorCode=@@ERROR
IF (@ErrorCode<>0) GOTO UpdateProblem
ELSE
COMMIT TRAN UpdateCourses
SELECT @CurrentSeats=OpenSeats
FROM dbo.Courses
WHERE dbo.Courses.CourseId = @CourseID
IF (@CurrentSeats<0) GOTO PROBLEM
ELSE
COMMIT TRAN Tr3
END
END
OTHERPROBLEM:
BEGIN
PRINT 'Unable to set status'
ROLLBACK TRAN
END
OTHERPROBLEM2:
BEGIN
PRINT 'Unable to set status'
ROLLBACK TRAN
END
UpdateProblem:
BEGIN
PRINT 'Not able to update values'
ROLLBACK TRAN InsertingValues
END
InsertProblem:
BEGIN
PRINT 'Not able to insert'
ROLLBACK TRAN InsertingValues
END
PROBLEM:
BEGIN
PRINT 'Seats Full!'
ROLLBACK TRAN
END
IF @StatusID = 1
BEGIN
SET @Status = 'The Student is already enrolled'
END;
ELSE IF @StatusID = 2
BEGIN
SET @Status = 'Cannot enroll until faculty is selected'
END
ELSE IF @StatusID = 3
BEGIN
SET @Status = 'Student Enrolled'
END
SELECT @Status
END;
这正确更新了表格，但出现以下错误:
This correctly updated the tables, but is giving the following errors:
(1 row(s) affected)
(1 row(s) affected)
Unable to set status
Msg 3903, Level 16, State 1, Procedure EnrollStudent, Line 101
The ROLLBACK TRANSACTION request has no corresponding BEGIN TRANSACTION.
Unable to set status
Msg 3903, Level 16, State 1, Procedure EnrollStudent, Line 108
The ROLLBACK TRANSACTION request has no corresponding BEGIN TRANSACTION.
Not able to update values
Msg 3903, Level 16, State 1, Procedure EnrollStudent, Line 115
The ROLLBACK TRANSACTION request has no corresponding BEGIN TRANSACTION.
Not able to insert
Msg 3903, Level 16, State 1, Procedure EnrollStudent, Line 123
The ROLLBACK TRANSACTION request has no corresponding BEGIN TRANSACTION.
Seats Full!
Msg 3903, Level 16, State 1, Procedure EnrollStudent, Line 131
The ROLLBACK TRANSACTION request has no corresponding BEGIN TRANSACTION.
(1 row(s) affected)
推荐答案
您得到的错误是因为您在没有打开事务的情况下回滚(您已经提交或回滚).考虑清理存储过程的结构，尝试将整个存储过程作为一个事务执行，然后在发生错误时回滚.您还可以通过检查事务是否打开来测试是否需要回滚:
The error you are getting is because you are rolling back without having an open transaction (you have either already committed or rolled-back). Consider cleaning up the structure of your stored proc, try executing your entire stored proc as one transaction, and then rolling back if an error occurs. You can also test if a rollback is required by checking if a transaction is open:
BEGIN TRANSACTION;
BEGIN TRY
--execute all your stored proc code here and then commit
COMMIT;
END TRY
BEGIN CATCH
--if an exception occurs execute your rollback, also test that you have had some successful transactions
IF @@TRANCOUNT > 0 ROLLBACK;
END CATCH
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