Question

I am working on triggers using SQL server 2005. I have a trigger for a table which is after update. After declaring the variables, the code is like this.

if @isconfirmed_before = 0 and @isconfirmed_after = 1
begin

if @invite_userid <> ''
        begin

            select @points = points from dbo.InvitePoint where code = 'USR' and packageid = @packageid
            INSERT INTO InviteCount
                   ([userID]
                   ,[joinMerchantID]
                   ,[packageID]
                   ,[points]
                   ,[joinDate])
             VALUES
                   (@invite_userid
                   ,@merchantid
                   ,@packageid
                   ,@points
                   ,getdate())
        end

 SET @alpha_numeric=''
        SELECT @alpha_numeric=@alpha_numeric+CHAR(n) FROM
        (
            SELECT TOP 8 number AS n FROM master..spt_values
            WHERE TYPE='p' and (number between 48 and 57 or number between 65 and 90)
            ORDER BY NEWID()
        ) AS t 

        update merchant
        set reg_code = @alpha_numeric
        where merchantid = @merchantid

END

The last part of

    update merchant  
    set reg_code = @alpha_numeric
    where merchantid = @merchantid

This reg_code shoule be inserted only once when the row is inserted but it is changing every time there is an update to the table. How do i make it happen. Please help me, Thank you in advance!!

Answer 1

update merchant   
set reg_code = @alpha_numeric 
where merchantid = @merchantid 

That code is executing every time there is an update, because you have no conditional flow preventing it from executing sometimes. If you want to only execute that given a certain condition, you’ll need to wrap it in an IF block.

You say: “This reg_code shoule be inserted only once when the row is inserted but it is changing every time there is an update to the table.” Why is that in an AFTER UPDATE trigger then? It looks like it should be in an AFTER INSERT trigger. Unless I am misunderstanding you.