数据SQL结构:
CREATE OR REPLACE TRIGGER <触发器名称>
BEFORE <触发条件>
ON <触发的表名>
referencing OLD ROW AS "OLD" NEW ROW AS "NEW"
for each row
BEGIN
<执行的SQL>;
END;
例如:每当表HEARTBEAT被更新时,自动更新UPDATED_AT的时间
CREATE OR REPLACE TRIGGER "TRG_UPDATE_ HEARTBEAT_UPDATE_TIME"
BEFORE UPDATE
ON "HEARTBEAT"
referencing OLD ROW AS "OLD" NEW ROW AS "NEW"
for each row
BEGIN
SET NEW.UPDATED_AT = CURRENT_TIMESTAMP;
END;