mysql存储过程实例演示

1:简单示例 加法

create definer=`root`@`%` procedure `add_procedure`(in a int,in b int,out sum int)

begin
declare c int;
    if a is null then set a = 0; 
    end if;
  
    if b is null then set b = 0;
    end if;


    set sum  = a + b;
end

调用：

call new_procedure(2,2,@s);
select @s as sum;

输出为4

2:查询某个表格所有数据

create definer=`root`@`%` procedure `select_all_procedure`()
begin
select count(*) from users;
end

调用

call new_procedure();

输出个数