Anyone recognise this error from PL/pgSQL?

Hi,

I'm trying my first PL/pgSQL code to trap foreign key errors. Before inserting
into the table "Exon", I wish to be sure that a foreign key, 'zhvtID', exists in
the table 'zhvt'. Sounds simple...

This is the code I use:

CREATE FUNCTION exon_foreign_keys() RETURNS opaque AS '
DECLARE
zhvt_row zhvt%ROWTYPE;
BEGIN
IF NEW.zhvtID ISNULL THEN
RAISE EXCEPTION ''zhvtID can not be NULL'';
END IF;

SELECT * INTO zhvt_row FROM zhvt
WHERE zhvtID=NEW.zhvtID;
IF NOT FOUND THEN
RAISE EXCEPTION ''zhvtID= % is not in TABLE zhvt'' , NEW.zhvtID;
END IF;
END;
' LANGUAGE 'plpgsql';

And this is the trigger I create to call the code upon insert:

CREATE TRIGGER check_exon_FK BEFORE INSERT OR UPDATE ON exon
FOR EACH ROW EXECUTE PROCEDURE exon_foreign_keys();

And this is the error I get when I try to insert anything, regardless of whether
the foreign key exists or not:

zhvt=> insert into exon (zhvtID, number, start, stop, iscomplement)
zhvt-> values (1, 1, 1, 100, 't');
ERROR: There is no operator '=$' for types 'int4' and 'int4'
You will either have to retype this query using an explicit cast,
or you will have to define the operator using CREATE OPERATOR

If I drop the trigger, the error goes away.

Any ideas?

Mark

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Mark Dalphin email: mdalphin(at)amgen(dot)com
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