在做一个邮件设置功能，由于数据库表设计者很蠢，导致查询起来很费劲，有的时候可能要将简单的查询根据条件不同执行很多次，很是让自己不开心。下面是一个与蠢人打交道的成功方案：

• 起初数据库里的数据是长这样的：

• 通过SQL查询出来的结果变成了想要的结果：
  

sql：

select
            tmp1.host_address,tmp2.host_port,tmp3.email_user_name,tmp4.email_password,tmp5.accept_email_address,tmp6.publicity_is_send
        from
            (select
                wmsys.wm_concat (value) as host_address
            from
                t_sys_setup
            where
                data_type in ('mail_server'))tmp1,(select
                wmsys.wm_concat (value) as host_port
            from
                t_sys_setup
            where
                data_type in ('mail_port'))tmp2,(select
                wmsys.wm_concat (value) as email_user_name
            from
                t_sys_setup
            where
                data_type in ('mail_account'))tmp3,(select
                wmsys.wm_concat (value) as email_password
            from
                t_sys_setup
            where
                data_type in ('mail_pwd'))tmp4,(select
                wmsys.wm_concat (value) as accept_email_address
            from
                t_sys_setup
            where
                data_type in ('addressee'))tmp5,(select
                wmsys.wm_concat (value) as publicity_is_send
            from
                t_sys_setup
            where
                data_type in ('issendmail'))tmp6