If the code in the COMMPLAN table is located, the description of the COMMPLAN is obtained and deposited in the non-database Description item. Otherwise, an error is raised.
/*
** Method 1: Using a SELECT...INTO statement, the trigger
** looks more readable but can be less efficient
** than Method 2 because for ANSI Standard
** compliance, the SELECT...INTO statement must
** return an error if more than one row is
** retrieved that matches the criteria. This
** implies PL/SQL may attempt to fetch data twice
** from the table in question to insure that there
** aren’t two matching rows.
*/
BEGIN
SELECT description
INTO :Employee.Commplan_Desc
FROM commplan
WHERE commcode = :Employee.Commcode;
EXCEPTION
WHEN No.Data_Found THEN
Message(’Invalid Commission Plan, Use <List> for help’);
RAISE Form_trigger_Failure;
WHEN Too_Many_Rows THEN
Message(’Error. Duplicate entries in COMMPLAN table!’);
RAISE Form_trigger_Failure;
END;
/*
** Method 2: Using an Explicit Cursor looks a bit more
** daunting but is actually quite simple. The
** SELECT statement is declared as a named cursor
** in the DECLARE section and then is OPENed,
** FETCHed, and CLOSEd in the code explicitly
** (hence the name). Here we guarantee that only a
** single FETCH will be performed against the
** database.
*/
DECLARE
noneFound BOOLEAN;
CURSOR cp IS SELECT description
FROM commplan
WHERE commcode = :Employee.Commcode;
BEGIN
OPEN cp;
FETCH cp INTO :Employee.Commplan_Desc;
noneFound := cp%NOTFOUND;
CLOSE cp;
IF noneFound THEN
Message(’Invalid Commission Plan, Use <List> for help’);
RAISE Form_trigger_Failure;
END IF;
END;
