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Select one set null instead of throwing exception

Guy Rouillier

2009-10-05

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Currently, performing a single row select throws an exception if zero or
> 1 rows are returned. While this is certainly workable, an
alternative that would be easier on the programmer would be to set the
result to null if no rows are found, and only throw an exception if > 1
rows are found.

The documentation suggests doing a count to determine what situation you
are in, then issuing the appropriate select once you know. But that
will result in an extra trip to the DB. In a common scenario where you
are querying a primary key, you know that you will get zero or one row
back. So rather than having to put the single row select into a
try-catch block, a more natural paradigm would be to assign the result
and then check the result for null.

--
Guy Rouillier

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