Question

I have two tables and I need to remove rows from the first table if an exact copy of a row exists in the second table.

Does anyone have an example of how I would go about doing this in MSSQL server?

Answer 1

Well, at some point you’re going to have to check all the columns – might as well get joining…

DELETE a FROM a  -- first table INNER JOIN b -- second table       ON b.ID = a.ID       AND b.Name = a.Name       AND b.Foo = a.Foo       AND b.Bar = a.Bar 

That should do it… there is also CHECKSUM(*), but this only helps – you’d still need to check the actual values to preclude hash-conflicts.