回滚 SQL 事务而不返回错误

Question

考虑下面的触发器

ALTER TRIGGER [dbo].[trgUpdateTasks] 
   ON  [dbo].[Tasks] 
   FOR UPDATE
AS 
BEGIN
    SET NOCOUNT ON;
    -- Check if job has quotation --
    DECLARE @JobID NUMERIC(18,0)
    DECLARE @QuotationID UNIQUEIDENTIFIER
    SELECT @JobID = INSERTED.JobID FROM INSERTED
    SET @QuotationID = (SELECT TOP 1 QuotationID FROM Jobs WHERE (JobID=@JobID))
    --------------------------------
    IF( NOT (@QuotationID IS NULL) )
    BEGIN
        ROLLBACK TRANSACTION;
    END;
END

这个想法是阻止对任务记录进行任何更改，如果它与在QuotationID字段中具有值的作业记录相关联。

它起作用是因为当满足这些条件时，不会保存更改。 但是，会向应用程序返回导致其崩溃的错误。 不幸的是，该应用程序无法更新以忽略此类错误，因为它运行在不允许安装较新 exe 的非常旧的 Windows 机器上。

有没有办法设置触发器在回滚时不返回错误，这样就应用程序而言，更改已正常保存？

Answer 1

/* *** DDL and Test Data *** */
USE tempdb;
GO
SET ANSI_NULLS, QUOTED_IDENTIFIER, ANSI_PADDING ON;
GO
CREATE TABLE dbo.Tasks
(
    TaskID int NOT NULL PRIMARY KEY
    ,JobID int NOT NULL
    ,Task varchar(50) NOT NULL
    ,TaskStart date NOT NULL
    ,TaskEnd date NULL
);
GO
INSERT INTO dbo.Tasks
VALUES (1, 1, 'Task1 Job1', '20210901', '20210902')
    ,(2, 1, 'Task2 Job1', '20210902', NULL)
    ,(3, 2, 'Task1 Job2', '20210903', '20210904')
    ,(4, 2, 'Task2 Job2', '20210905', '20210906')
    ,(5, 3, 'Task1 Job3', '20210910', '20210911')
    ,(6, 3, 'Task2 Job3', '20210915', NULL)
    ,(7, 4, 'Task1 Job4', '20210903', '20210904')
    ,(8, 4, 'Task2 Job4', '20210905', '20210906');
GO
CREATE TABLE dbo.Jobs
(
    JobID int NOT NULL PRIMARY KEY
    ,QuotationID uniqueidentifier NULL
    ,Job varchar(50) NOT NULL
);
GO
INSERT INTO dbo.Jobs
VALUES (1, 'F15EAF03-4F45-40E8-85D6-D89B20E00F38', 'Job1')
    ,(2, NULL, 'Job2')
    ,(3, 'F15EAF03-4F45-40E8-85D6-D89B20E00F38', 'Job3')
    ,(4, '3D74F043-2FAC-4C91-8288-13D71C6558C8', 'Job4');
GO
/* *** End DDL and Test Data *** */

/* *** Create Trigger *** */
SET ANSI_NULLS, QUOTED_IDENTIFIER ON;
GO
CREATE TRIGGER dbo.Tasks_TR_U
ON dbo.Tasks
INSTEAD OF UPDATE
AS
BEGIN
    SET NOCOUNT, XACT_ABORT ON;

    UPDATE T
    SET Task = I.Task
        ,TaskStart = I.TaskStart
        ,TaskEnd = I.TaskEnd
    FROM dbo.Tasks T
        JOIN inserted I
            ON T.TaskID = I.TaskID
    WHERE EXISTS
    -- Only QuotationID of NULL allowed
    (
        SELECT 1
        FROM dbo.Jobs J
        WHERE J.JobID = T.JobID
            AND J.QuotationID IS NULL
    )
        -- Only update if any changes
        AND NOT
        (
            T.Task = I.Task
            AND T.TaskStart = I.TaskStart
            AND ISNULL(T.TaskEnd, '1900') = ISNULL(I.TaskEnd, '1900')
        );
END
GO
/* *** End Create Trigger *** */


/* Check data in tables. */
select * from dbo.Tasks;
select * from dbo.Jobs;

/* Run test */
UPDATE dbo.Tasks
SET Task = Task + ' Updated'

/* Only JobId = 2 should be updated. */
select * from dbo.Tasks;

/* Drop Test Tables
DROP TABLE dbo.Tasks;
DROP TABLE dbo.Jobs;
*/

Answer 2

如果您使用而不是触发器，您只需要在quotation_id 为空时更新。 此外，触发器中不应该有变量，因为它应该允许一次更新多行。