MYSQL数据库防止mysql表被清空的方法详解

t_girl=# create role ytt3 with login connection limit 1 password 'ytt3';
create role
t_girl=# alter schema ytt owner to ytt3;
alter schema
t_girl=# grant select on all tables in schema ytt to ytt3;
grant

bash-4.1$ psql -u ytt3 t_girl
psql (9.3.4)
type "help" for help.
t_girl=> truncate table j2;
error: permission denied for relation j2

t_girl=# sf prevent_truncate
create or replace function public.prevent_truncate()
 returns trigger
 language plpgsql
as $functio$
begin
raise exception 'prevent "%" to be truncated!', tg_table_schema||tg_table_name;
return new;
end;
$function$MYSQL教程

t_girl=# d j2
        table "ytt.j2"
 column | type | modifiers
--------+---------+-----------
 id | integer |
 str2 | text |
triggers:
    trigger_truncate_before before truncate on j2 for each statement execute procedure ytt.prevent_truncate()MYSQL教程

t_girl=#MYSQL教程

t_girl=# truncate table j2;
error: prevent "ytt.j2" to be truncated!MYSQL教程

mysql> truncate table j2;
error 1142 (42000): drop command denied to user 'ytt3'@'localhost' for table 'j2'

+------------------------------------+
| error |
+------------------------------------+
| prevent t_girl.j2 to be truncated! |
+------------------------------------+
1 row in set (0.00 sec)