I was wondering the other day if it would be possible to use exim's SQL
based lookups to perform inserts into a database. From looking at the code
in Exim, I can see this is not possible because the Exim SQL lookups check
that a result set with data is returned. If a result set and data are not
returned the lookups fail.
From quickly reviewing the code it looks like it would be possible to modify
it to allow both select queries & insert / update queries. The postgres &
mysql lookup drivers already to check that the query executed properly.
Leave that part of the code as is, and add code to fail if the query itself
had a problem. Modify the code that retrieves the result data to check if
there was a result set returned. If one was returned, and there is a
problem processing it, fail.. If no result set was returned, then don't try
to process one, and don't fail.
