oracle 触发器A、B表关联更新

Question

oracle 触发器，插入或更新A表时，更新A表MEMO字段，字段内容取于B表MEMO字段。A、B表关联字段A.ID=B.ID

Answer 1

这不是刚学触发器的基本问题吗。

CREATE /REPLACE TRIGGER Test
AFTER INSERT OR UPDATE ON A
FOR EACH ROW
DECLARE
  memo_value B.MEMO%TYPE;
BEGIN
  SELECT MEMO INTO memo_value FROM B WHERE B.ID = :NEW.ID;
  UPDATE A SET MEMO = memo_value WHERE ID = :NEW.ID;
END;