Question

I created this pretty basic stored procedure, that gets called by our cms when a user creates a specific type of item. However, it looks like there are times when we get two rows for each cms item created with the same data, but an off-by-one SourceID. I don’t do much SQL work, so this might be something basic – but do I need to explicitly lock the table somehow in the stored procedure to keep this from happening?

Here is the stored procedure code:

BEGIN
    SET @newid = (SELECT MAX(SourceID)+1 from [dbo].[sourcecode])

    IF NOT EXISTS(SELECT SourceId from [dbo].[sourcecode] where SourceId = @newid)
        INSERT INTO [dbo].[sourcecode]
            (
                SourceID,
                Description,
                RunCounts,
                ShowOnReport,
                SourceParentID,
                ApprovedSource,
                Created
            )
        VALUES
            (
                @newid,
                @Desc,
                1,
                @ShowOnReport,
                1,
                1,
                GetDate()
            )

    RETURN @newid
END

and here is an example of the duplicated data (less a couple of irrelevant columns):

SourceId    Description Created
676         some text   2012-10-17 09:42:36.553
677         some text   2012-10-17 09:43:01.380

Answer 1

I am sure this has nothing to do with SP. As Oded mentioned, this could be the result of your code.
I don’t see anything in the stored procedure which is capable of generating duplicates.
Also, I wouldn’t use MAX(SourceId) + 1. Why don’t you use “Auto Increment” if you want a new Source Id all the time anyways?