sql - 使用 group by 在 sql 查询中出错

Question

我尝试运行如下 sql 查询(mssql 2005):

select top 20 d_date, date1, date2 
from reestr_calculated 
where reestr_id=2 
group by date2 
order by date2 desc

我收到以下错误:

Column 'reestr_calculated.d_date' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.

有谁知道我该如何处理这个错误？

Answer 1

当您使用 GROUP BY ，多行“折叠”为一行。要确定应显示组中的哪些行，您必须使用聚合函数。

赞 MIN()或 SUM()或其他。

像这样:

select top 20 MIN(d_date), MAX(date1), date2 
from reestr_calculated 
where reestr_id=2 
group by date2 
order by date2 desc

或者像这样:

select top 20 d_date, date1, date2 
from reestr_calculated 
where reestr_id=2 
group by d_date, date1, date2 
order by date2 desc