sql - 选择对行进行分组

Question

我有一张这样的桌子：

Alternative |Total  |Male  |Female
a           |20     |10    |10
b           |50     |20    |30 
c           |40     |10    |30 
c           |30     |15    |15 

现在我想选择所有行和要分组的“c”替代项。

Answer 1

SELECT Alternative, Sum(Total), Sum(Male), Sum(Female) 
FROM table1 
GROUP BY Alternative

Answer 2

这应该足够了

SELECT Alternative, [Total] = SUM(Total), [Male] = SUM(Male), [Female] = SUM(Female)
FROM YourTable
GROUP BY Alternative

Answer 3

用于group by确定分组，然后使用适当的聚合处理其他字段。我相信在这种情况下，您想用来sum添加每个组中的值：

select
   Alternative, sum(Total) as Total, sum(Male) as Male, sum(Female) as Female
from
   TheTable
group by
   Alternative
order by
   Alternative

Answer 4

以下查询将选择所有不是“c”的行，然后对所有“c”的行进行分组，将它们的值相加，并添加一个表示“c”和的单行。我希望这就是你的意思。

SELECT *
FROM table1 
WHERE Alternative != c

UNION

SELECT Alternative, Sum(Total) as Total, Sum(Male) as Male, Sum(Female) as Female
FROM table1 
WHERE Alternative = c
GROUP BY Alternative

如果您只想对具有多个“替代”外观的任何内容进行分组，只需使用：

SELECT Alternative, Sum(Total) as Total, Sum(Male) as Male, Sum(Female) as Female
FROM table1 
GROUP BY Alternative