触发无效和重新验证错误

Question

我已执行下一个查询并出现“触发无效和重新验证”错误。这个查询有什么问题

CREATE OR REPLACE TRIGGER t
  BEFORE
    INSERT OR
    UPDATE OF sal, deptno OR
    DELETE
  ON emp
BEGIN
  CASE
    WHEN INSERTING THEN
      DBMS_OUTPUT.PUT_LINE('Inserting');
    WHEN UPDATING('sal') THEN
      DBMS_OUTPUT.PUT_LINE('Updating salary');
    WHEN UPDATING('deptno') THEN
      DBMS_OUTPUT.PUT_LINE('Updating department ID');
    WHEN DELETING THEN
      DBMS_OUTPUT.PUT_LINE('Deleting');
  END CASE;
END;