MySQL log trigger implementation code

SQL statement

DROP TRIGGER
IF
EXISTS sys_menu_edit;
CREATE TRIGGER sys_menu_edit BEFORE UPDATE ON sys_menu FOR EACH ROW
BEGIN
INSERT INTO `g4m`.`sys_log` ( `table_name`, `val_id`, `data_json` )
VALUES
(
'sys_menu',
old.id,
CONCAT(
"{",
CONCAT_WS(
',',
CONCAT_WS( old.id, '"id":"', '"' ),
CONCAT_WS( old.CODE, '"code":"', '"' ),
CONCAT_WS( old.type_dic, '"type_dic":"', '"' ),
CONCAT_WS( old.NAME, '"name":"', '"' ),
CONCAT_WS( old.pid, '"pid":"', '"' ),
CONCAT_WS( old.status_dic, '"status_dic":"', '"' ),
CONCAT_WS( old.url, '"url":"', '"' ),
CONCAT_WS( old.path, '"path":"', '"' ),
CONCAT_WS( old.icon, '"icon":"', '"' ),
CONCAT_WS( old.sort, '"sort":"', '"' ),
CONCAT_WS( old.remark, '"remark":"', '"' ),
CONCAT_WS( old.create_time, '"create_time":"', '"' ),
CONCAT_WS( old.modify_uer_id, '"modify_uer_id":"', '"' ),
CONCAT_WS( old.modify_time, '"modify_time":"', '"' )
),
"}"
)
);

MySQL uses triggers to implement logging

CREATE TRIGGER news_log AFTER INSERT ON news;
FOR EACH ROW INSERT INTO `news_logs` select *, now() from news where newsid = (select max(newsid ) from news);
DROP TRIGGER news_log;

There are two tables in total, one is the original table news, and the other is the log table news_logs (with an additional date column), which can automatically record logs when new entries are inserted without writing code. Similarly, you can also insert update logs when updating. For details, see the MySQL documentation.

mysql uses triggers to record operations

MySQL cannot perform insert, update, and delete operations in one trigger. You need to create three triggers separately.

Insert trigger:

delimiter $$
create trigger tri_city_insert
after insert 
on t_xfw_city 
for each row
begin
  insert into t_tri_city(id,name,provinceid,ctype) 
  values(new.id,new.name,new.provinceid,1);
end

Update trigger:

delimiter $$
create trigger tri_city_update
after update 
on t_xfw_city 
for each row
begin
  insert into t_tri_city(id,name,provinceid,ctype) 
  values(new.id,new.name,new.provinceid,2);
end

Delete trigger:

delimiter $$
create trigger tri_city_delete
after delete 
on t_xfw_city 
for each row
begin
  insert into t_tri_city(id,name,provinceid,ctype) 
  values(old.id,old.name,old.provinceid,3);
end

It is a bit troublesome to create three triggers for one table. I wonder if there is a better way.

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