Hi folks,
I got an problem that's being on my mind for a couple of days. I've thought
about different solution methods, but everything seems to be worse than the
problem itself.
I got a very simple lookup table with only one column 'name'. Its data type
is VarChar(50) and it's unique, so there can't be any duplicate entries.
Problems is that unique is case-sensitive. Germans tend to capitalize the
first letter of every word. But if anone doesn't do that, or if he
accidentially acps any letter, then this forms a new valid entry. So there
could be two entries representing the same thing, e.g 'Phenytoin' and
'phenytoin'.
How can this problem be overcome? Any ideas?
One solution I found is a before-trigger that checks whether the table
already contains a similar entry:
CREATE FUNCTION test_drug () RETURNS OPAQUE AS ' BEGIN IF (SELECT name from drug WHERE lower(name) =
lower(NEW.name))ISNULL
THEN RETURN NEW; ELSE RAISE EXCEPTION ''Lookup table cannot have duplicate entries''; END
IF; END;
' LANGUAGE 'plpgsql';
CREATE TRIGGER drug_insert BEFORE UPDATE OR INSERT ON drug FOR EACH ROW EXECUTE PROCEDURE test_drug();
This solution seems pretty complicated to me. Worst thing is that I have to
write a test function for every lookup table, since I don't know how to
place the lookup table's name in the SELECT-statement. Any ideas for that?
Greetings,
Joerg
