求一MySql查询语句 table a:aid na nb0 1 21 1 32 3 2查询结果:nab123结果为字段na和字段nb的记录去除重复后的汇总。 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 select nabfrom (select na as nab from aunionselect nb as nab fromm a)Torder by T.nab 有错误:Unknown column 'T.nab' in 'field list' 哦,我写错了,没注意nab必须一样:select nabfrom (select na as nab from aunionselect nb as nab fromm a)Torder by T.nab 错了select nabfrom (select distinct na as nab from aunionselect distinct nb as nab fromm a)Torder by T.na 上面那个对的,第二次发的错的:Unknown column 'T.na' in 'order clause'而且,第一次的那个没有加distinct 也有过滤重复的效果只是,有没有简单点的?写sql语句和执行都比较麻烦…… select nabfrom (select distinct na as nab from aunionselect distinct nb as nab fromm a)Torder by T.nab第一个貌似错了吧 第一个的结果集你看了吗 看了,可以查出来:nab123第二个会提示:Unknown column 'T.na' in 'order clause' 纠结的mysql连接问题 想问一下最新发布的mysql 5.5.x有什么新特性好用吗? mysql分表同步的问题 mysql 数据表对性能有何影响。 用Toad for MySQL没法建外键? 求MySQL一个两表查询的语句 MySQL新手急问 mysql安装系统服务问题 求教了....字符串包含问题! 怎样使用mysql的jdbc驱动程序? mysql 触发器怎么写 主主同步可否忽略某个字段
from (
select na as nab from a
union
select nb as nab fromm a
)T
order by T.nab
Unknown column 'T.nab' in 'field list'
select nab
from (
select na as nab from a
union
select nb as nab fromm a
)T
order by T.nab
select nab
from (
select distinct na as nab from a
union
select distinct nb as nab fromm a
)T
order by T.na
Unknown column 'T.na' in 'order clause'
而且,第一次的那个没有加distinct 也有过滤重复的效果
只是,有没有简单点的?写sql语句和执行都比较麻烦……
from (
select distinct na as nab from a
union
select distinct nb as nab fromm a
)T
order by T.nab
第一个貌似错了吧 第一个的结果集你看了吗
nab
1
2
3
第二个会提示:
Unknown column 'T.na' in 'order clause'