Mysql 存储过程使用Cast()

[yangpan010101]

delimiter //
CREATE PROCEDURE dnt_getuserlist()
begin
declare pagesize int;
declare pageindex int;
declare orderby varchar(200);
DECLARE pagetop int;
DECLARE `sql` varchar(1000);
SET pagetop = (pageindex-1)*pagesize;
IF pageindex = 1 then
SET `sql`= 'SELECT TOP ' + CAST(pagesize AS varchar(10)) + ' [dnt_users].[uid],
FROM [dnt_users] LEFT JOIN [dnt_userfields] ON [dnt_userfields].[uid] = [dnt_users].[uid] ' + orderby;
ELSE
SET `sql` = 'SELECT TOP ' + CAST(pagesize AS varchar(10)) + ' [dnt_users].[uid], [dnt_users].[username], [dnt_users].[nickname], [dnt_users].[joindate], [dnt_users].[credits], [dnt_users].[posts], [dnt_users].[email], [dnt_users].[lastactivity], [dnt_userfields].[location] FROM [dnt_users] LEFT JOIN [dnt_userfields] ON [dnt_userfields].[uid] = [dnt_users].[uid] WHERE [dnt_users].[uid] NOT IN (SELECT TOP ' + CAST(pagetop AS varchar(10)) + ' [uid] FROM [dnt_users] ' + orderby + ') '+ replace(orderby,'WHERE','AND');
END IF;
select `sql`;
call `sql`;
end;//

该存储过程在 CAST(pagesize AS varchar(10))附近报错，请问是哪里错了，mysql里不能这样写吗？

[ACMAIN_CHM]

mysql> delimiter //
mysql> CREATE PROCEDURE dnt_getuserlist()
    -> begin
    -> declare pagesize int;
    -> declare pageindex int;
    -> declare orderby  varchar(200);
    -> DECLARE pagetop int;
    -> DECLARE `sql` varchar(1000);
    -> SET pagetop = (pageindex-1)*pagesize;
    -> IF pageindex = 1 then
    ->          SET `sql`= concat( 'SELECT TOP ' , pagesize , ' [dnt_users].[uid] FROM [dnt_users] LEFT JOIN [dnt_userfields] ON [dnt_userfields].[uid]   = [dnt_users].[uid] ' , orderby);
    -> ELSE
    ->          SET `sql` = concat('SELECT TOP ' , pagesize , ' [dnt_users].[uid], [dnt_users].[username], [dnt_users].[nickname], [dnt_users].[joindate], [dnt_users].[credits], [dnt_users].[posts], [dnt_users].[email], [dnt_users].[lastactivity], [dnt_userfields].[location] FROM [dnt_users] LEFT JOIN [dnt_userfields]ON [dnt_userfields].[uid] = [dnt_users].[uid] WHERE [dnt_users].[uid] NOT IN (SELECT TOP ' , pagesize , ' [uid] FROM [dnt_users]  ' , orderby , ') ', replace(orderby,'WHERE','AND'));
    -> END IF;
    -> select `sql`;
    ->   set @sSQL=`sql`;
    ->  PREPARE  stmt1 FROM   @sSQL;
    ->  EXECUTE stmt1 ;
    ->  DEALLOCATE PREPARE stmt1;
    ->
    -> end;//
Query OK, 0 rows affected (0.00 sec)

mysql> delimiter ;
mysql>

[ACMAIN_CHM]

1、MYSQL 中字符中相加不是用+号，而是CONCAT（）
2、MYSQL不需要做CAST，另外CAST函数的语法也和MS SQL SERVER也不同。
3、MYSQL中动态执行SQL语句用的是PREPARE/EXECUTE

具体语法说明你可以参考一下官方手册的说明和例子。

MySQL官方文档 http://dev.mysql.com/doc/refman/5.1/zh/index.html