mysql存储过程写法—动态参数运用
时间：2022-03-13 23:32
--删除
| 1 |
drop procedure if exists up_common_select
|
--创建
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 |
CREATE PROCEDURE `up_common_select`
(
in t_name varchar(50)
)
begin
declare v_sql varchar(500);
set v_sql= concat(‘select * from ‘,t_name);
select v_sql;
--注意:prepare(预处理)execute stmt using @var,只能跟@var变量,declare和传入的变量不行!!!
set @v_sql=v_sql;
prepare stmt from @v_sql;
EXECUTE stmt ;
deallocate prepare stmt;
end;
|
--调用
| 1 |
call up_common_select(‘admin_authority‘);
|
注意事项
1 mysql5.0.13之后支持在存储过程中调用prepare
2 prepare stmt from ‘select * from ?‘; (错)
mysql5.0.24,prepare尚不支持 表名做变量!
解决方案:用 contat()函数,组合字符串
3 execute stmt [using @var,@var2]
必须是@var形式的变量,传入的参数变量,declare变量不行
4. deallocate prepare stmt; 显式的释放prepare,如果不释放,mysql会释放,!
