Great article, just what I needed. Thanks

I made a slight modification in the CSD2 variant, just for security, to avoid ererroneous data, when the procedure is executed on an earlier day, than the last update.

I admit, this does not happen when using GETDATE() to set today, but my procedure has a date input, so I decided to be sure no updates are made on records which have ValidFrom > @Today.

So I added a statement to the WHEN MATCHED condition:

WHEN MATCHED

AND IsCurrent = 1

AND ValidFrom <= @Today --Never allow updates to overwrite future records

AND (ISNULL(DST.ClientName,'') <> ISNULL(SRC.ClientName,'')

...

Thanks once more

Herman