Hello, the construct surprised me when I saw it in the function the first time, but it is correct and works as expected - it allows writing the function as SQL instead of PLPGSQL while it ensures that for a parameter null value it evaluates to true instead of filtering the resultset. What is the issue/better solution proposal?
Kind regards Ales Zeleny čt 4. 8. 2022 v 23:15 odesílatel Joe Conway <m...@joeconway.com> napsal: > On 8/4/22 08:34, Aleš Zelený wrote: > >> SELECT ... simple join of two tables... > >> WHERE opd.id_data_provider = _id_data_provider > >> AND CASE WHEN _external_id IS NULL > >> THEN external_id IS NULL > >> ELSE external_id = _external_id > >> END > >> AND CASE WHEN _external_complete_id IS NULL > >> THEN _external_complete_id IS NULL > > Unrelated to your question, but shouldn't that actually read: > > AND CASE WHEN _external_complete_id IS NULL > THEN external_complete_id IS NULL > ^^^ > > >> ELSE external_complete_id = _external_complete_id > >> END; > >> $function$ > > -- > Joe Conway > RDS Open Source Databases > Amazon Web Services: https://aws.amazon.com >
