試題詳解

QUESTION 73 Examine the trigger heading: CREATE OR REPLACE TRIGGER salary_check BEFORE UPDATE OF sal, job ON emp FOR EACH ROW Under which condition does this trigger fire?
(A) When a row is inserted into the EMP table.
(B) When the value of the SAL or JOB column in a row is updated in the EMP table.
(C) When any column other than the SAL and JOB columns in a row are updated in the EMP table.
(D) Only when both values of the SAL and JOB columns in a row are updated together in the EMP table.