我要评论1.创建test3：create databse test3；
2.创建表t2：
use test3;
create table t2 (id int,name char(50),dtime timestamp);
mysql> select * from t2; empty set (0.00 sec)
3.创建procedure来循环插入数据到新建的t2表中，创建trigger禁止插入数据如果该表行数达到12
mysql> delimiter $$
mysql> create procedure t2insert(in count int)
-> begin
-> declare i int default 0;
-> while i do
-> insert into t2 values(i,concat('yoo',i),current_timestamp());
-> set i=i+1;
-> end while ;
-> end$$
query ok, 0 rows affected (0.06 sec)
mysql> create trigger tr701 before insert on t2 for each row
-> begin
-> declare msg varchar(50);
-> set msg="row is over 11,cannot insert again";
-> set @num=(select count(* ) from t2);
-> if @num >11 then
-> signal sqlstate 'hy000' set message_text=msg;
-> end if;
-> end$$
query ok, 0 rows affected (0.11 sec)
4.查看存储过程和trigger的信息：
delimiter ;
show procedure status like '%insert%' \g;
show create procedure t2insert \g;
select * from information_schema.routines where routine_name = 't2insert' \g;
show triggers tr701\g
select * from information_schema.triggers where trigger_name like '%tr%'\g
mysql> show procedure status like '%insert%' \g;
*************************** 1. row ***************************
db: test3
name: t2insert
type: procedure
definer: root@localhost
modified: 2018-06-10 22:13:09
created: 2018-06-10 22:13:09
security_type: definer
comment:
character_set_client: gbk
collation_connection: gbk_chinese_ci
database collation: utf8_general_ci
1 row in set (0.00 sec)
5.调用存储过程：
mysql> call t2insert(10); query ok, 1 row affected (0.65 sec) mysql> select * from t2; +------+------+---------------------+ | id | name | dtime | +------+------+---------------------+ | 0 | yoo0 | 2018-06-10 22:18:25 | | 1 | yoo1 | 2018-06-10 22:18:26 | | 2 | yoo2 | 2018-06-10 22:18:26 | | 3 | yoo3 | 2018-06-10 22:18:26 | | 4 | yoo4 | 2018-06-10 22:18:26 | | 5 | yoo5 | 2018-06-10 22:18:26 | | 6 | yoo6 | 2018-06-10 22:18:26 | | 7 | yoo7 | 2018-06-10 22:18:26 | | 8 | yoo8 | 2018-06-10 22:18:26 | | 9 | yoo9 | 2018-06-10 22:18:26 | +------+------+---------------------+ 10 rows in set (0.00 sec)
6.测试触发器
mysql> insert into t2 values(10,'foo',current_timestamp()); query ok, 1 row affected (0.06 sec) mysql> insert into t2 values(11,'foo2',current_timestamp()); query ok, 1 row affected (0.11 sec) ----当插入条目达到12，就拒绝插入并抛出错误信息： mysql> insert into t2 values(12,'foo3',current_timestamp()); error 1644 (hy000): row is over 11,cannot insert again
7.可以使用alter修改存储过程的简单特性但并不能修改过程体,所以要修改过程体的sql语句只能
drop删除后重新创建
alter procedure
drop procedure t2insert;
drop trigger i701；
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