mysql - 如何在mysql中对一些值进行求和并将它们分组

Question

我有这样的表A:

我想得到这样的结果查询:

我怎样才能实现这个目标？

Answer 1

我认为你的总结果可能是45。结果75是从哪里来的？我不太清楚。如果你想要45，你可以使用以下查询

    select case When a.Item IS NULL THEN 'total' Else  a.Item  END AS Item,sum(a.value) as value from
     (select Item,sum(value) as value from test1 as t1 where t1.Item='A' or t1.Item='B'   group by  t1.Item )
    as a group by a.Item WITH ROLLUP