Question

我正在尝试group by。但是，这个唯一的id字段阻止我这样做。

您能帮我解决一下这个问题。

感谢。

方案1

select box.name, box.description, box.id
from box
group by box.name, box.description, box.id
order by box.id

更新：我已经解决了第一个场景 http://sqlfiddle.com/#!6/111e7/16/0

方案2

select box.name, box.description, box.id, sum(box.amount) as amount
from box
group by box.name, box.description, box.id
order by box.id

更新：我已经解决了第二种情况 http://sqlfiddle.com/#!6/449b7/2

Answer 1

删除重复

;WITH xx AS
(
    select 
        [rn] = ROW_NUMBER() OVER (PARTITION BY ID, ORDER BY Id),
        name, description, id
    from box    
) 
SELECT 
*
FROM xx
WHERE 
    [rn] = 1

或者

SELECT TOP 1 WITH TIES
*
FROM xx
ORDER BY 
    ROW_NUMBER() OVER (PARTITION BY ID ORDER BY Id)

Answer 2

一种方法是保持MAX或MIN框ID并使用它来排序。这将删除重复项，仍然为您提供订购价值。例如（使用MAX）

select box.name, box.description, MAX(box.id) box_id, sum(box.amount) as amount
from box
group by box.name, box.description, box.id
order by MAX(box.id)

通过拥有唯一ID来分组

2 个答案: