Any way to handle exceptions in PL/pgSQL ?

Is there any way to handle failed queries in PL/pgSQL?

<< I am aware that the example can be re-worded in a single query; This
is a question more on how to do the 'procedural' part >>

Example:1st queryif OK, return result2ne queryif OK, return resultreturn error message

Is it correct, that if a function fails, it returns null ??


-- Function: message_get(varchar)
CREATE FUNCTION message_get(varchar) RETURNS varchar AS '
DECLAREp_key ALIAS FOR $1;v_RetValue Message.MsgText%TYPE;
BEGINSELECT MsgText INTO v_RetValue FROM User_Message WHERE Value = p_Value;-- if ok ??RETURN v_RetValue;
SELECT Text INTO v_RetValue FROM Sys_MessageWHERE Value = p_Value;-- if ok ??RETURN v_RetValue;
RETURN 'nothing found';
END;
' LANGUAGE 'plpgsql';

Cheers,

Jorg Janke      (203) 445-9503                   http://www.compiere.org
Smart ERP & CRM Business Solution for Distribution and Service  globally
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