mysql 存储过程　怎么定义变量　请问

mysql 存储过程　如何定义变量　请教
MSSQL　sql server 2000写法
go
create proc loadUser
@uname varchar(16),
@upwd varchar(16),
@count int output
as
select * from users where uname=@uname and upwd=@upwd

if(@@error=0 and @@rowcount = 1)
set @count = 1;
else set @count=0;

go
在Mysql 当中怎么写呀　
如何　定义一个变量　
create procedure login(uname varchar(64),upwd varchar(64),out counts int)
[color=#00FFFF]DECLARE iCount int;
begin
SET iCount = 10;  
SELECT iCount;
end[/color]

对了请问下　IF EXISTS(SELECT * FROM sysdatabases WHERE name='bookshop')　这样的语句　mysql 支持吗？就是
判断　有没有查出内容来？？

[解决办法]


如何　定义一个变量
你的方法是对的，用 DECLARE iCount INT; 来定义变量。

IF EXISTS(。。。)这种语句目前还不被MySQL 5.x支持，实现相同功能的做法是再定义一个变量，然后利用select .. into来对这个变量赋值，然后判断是否exists符合条件的记录。如果多记录，可以改为 select count(*) into ..

SQL code

mysql> delimiter //mysql>mysql> CREATE PROCEDURE login (uname varchar(64),upwd varchar(64),out counts int)    ->   BEGIN    ->     DECLARE iCount INT;    ->     DECLARE bExist INT DEFAULT 0;    ->    ->     SET iCount = 10;    ->    ->  SELECT 1 into bExist FROM t WHERE name=uname; #use the variable to check the IF EXISTS    ->    ->  IF bExist>0 then    ->          SELECT  iCount,'Record Found.';    ->  ELSE    ->          SELECT  iCount,'NOT EXISTS';    ->  END IF;    ->    ->   END;    ->    -> //Query OK, 0 rows affected (0.00 sec)mysql>mysql> delimiter ;mysql> call login('f3','pswd',@i);+--------+---------------+| iCount | Record Found. |+--------+---------------+|     10 | Record Found. |+--------+---------------+1 row in set (0.00 sec)Query OK, 0 rows affected (0.02 sec)mysql> call login('unkonw','pswd',@i);+--------+------------+| iCount | NOT EXISTS |+--------+------------+|     10 | NOT EXISTS |+--------+------------+1 row in set (0.00 sec)Query OK, 0 rows affected, 1 warning (0.02 sec)mysql>
[解决办法]
好像能用吧，我的存储过程就是是这样写的，没有报错呀
[解决办法]
DECLARE  iCount  int;
begin
SET  iCount  =  10;  
SELECT  iCount;  

MYSQ中是可以的

对了请问下　IF EXISTS(SELECT * FROM sysdatabases WHERE name='bookshop')　这样的语句　mysql 支持吗？就是
判断　有没有查出内容来？？

select count(*) into @ee FROM sysdatabases WHERE name='bookshop'
if @ee>1 then
select 'OK';
ELSE
select 'NO';
END IF