Question

I have a trigger in a table in SQL Server 2000, this is the trigger:

ALTER Trigger [dbo].[Set_Asignado_State] ON [dbo].[Tables]  FOR INSERT AS  BEGIN                DECLARE @area varchar(1)     SELECT @area = Table_Area_ID FROM inserted      IF (@area = 'L')     BEGIN         INSERT INTO Table_History         SELECT  (SELECT TOP 1 Table_Area_Id AS Table_Area_Id FROM inserted) AS Table_Area_Id,                 (SELECT SUBSTRING( CAST( YEAR( GETDATE() ) AS VARCHAR), 3, 2) ) AS Table_Year,                  (SELECT TOP 1 Table_Seq AS Table_Seq FROM inserted) AS Table_Seq,                  (SELECT TOP 1 ID FROM Table_Status WHERE Description = 'Asignado') AS Status,                  '' AS Responsible,                  (SELECT TOP 1 OrigDept FROM inserted) AS User_Responsible,                  GETDATE() AS [DateTime],                 'None' AS Comments         FROM Tables         WHERE Tables.Table_Area_Id = (SELECT TOP 1 Table_Area_Id AS Table_Area_Id FROM inserted) AND               Tables.Table_Year = (SELECT SUBSTRING(CAST(YEAR(GETDATE()) AS VARCHAR), 3, 2) )          IF @@ERROR <> 0         BEGIN             DECLARE @errorMsg NVARCHAR(256)             SET @errorMsg = @@ERROR;               PRINT 'Error Inserting in Table_History'          END     END END 

Now, when they insert a record in ‘Tables’, the trigger is called but it keeps inserting many, many records on Table_History.

I’ve talked with my peers and there seems that there is nothing wrong! =S Any clues about this? Am I doing something wrong?

Thanks in advance =)

Answer 1

Triggers are set based, so doing
IF (@area = 'L') will only look at the first record from the inserted table. Try adding the check as part of your WHERE clause:

WHERE Tables.Table_Area_Id = (SELECT TOP 1 Table_Area_Id AS Table_Area_Id FROM inserted) AND               Tables.Table_Year = (SELECT SUBSTRING(CAST(YEAR(GETDATE()) AS VARCHAR), 3, 2) )    AND SUBSTRING(Tables.Table_Area_Id, 1, 1) = 'L' 

Are you sure that the main Select statement does only return the one row? I have noticed that you have used the Top(1) qualifier extensively. If it returns more than one row then there will be more than one row inserted into your history table.

Perhaps as a blind shot, try putting in a Top(1) for the outermost select:

    INSERT INTO Table_History     SELECT TOP(1) (SELECT TOP 1 ... 

Otherwise it looks as though you have some recursion going on in the trigger. I cannot see it, but if you want, you can turn off recursive triggering for the whole database, since it is a database option.