比如:`server_id` varchar(2) NOT NULL default '',
手动转化类型:
select server_id from cardserver where game_id = 1 order by server_id+0 desc limit
使用MySQL函数CAST/CONVERT:
select server_id from cardserver where game_id = 1 order by CAST(server_id as SIGNED) desc limit 10;
select server_id from cardserver where game_id = 1 order by CONVERT(server_id,SIGNED) desc limit 10;
cast跟convert的用法如下 signed 后面还有个INTEGER 可以不写的
用CAST函数或者CONVERT
CAST(expr AS type), CONVERT(expr,type) , CONVERT(expr USING transcoding_name)
CAST() 和CONVERT() 函数可用来获取一个类型的值,并产生另一个类型的值。
这个类型 可以是以下值其中的 一个:
BINARY[(N)]
CHAR[(N)]
DATE
DATETIME
DECIMAL
SIGNED [INTEGER]
TIME
UNSIGNED [INTEGER]