I am aware of the
NULLIF function which compares two values and returns
NULL if they match.
Is there a function which will compare two values and return
NULL if they don’t match? That is filter out the other values.
I know I can do something like that using
CASE column WHEN value THEN 1 END
I also know that I can write a function.
Perhaps there is a subtle trick to using
NULLIF that I am unaware of.
I have listed a few versions of SQL in the tags, but I think
NULLIF is generic. I am looking for a solution which is also generic, so that it can be applied to any standard database.