Question

这可能是一个非常基本的问题，但我试图在给定的月份内生成订单总值（不包括运费和税收）的直方图。

不幸的是，表格中没有列的总数，因此需要根据小计减去任何折扣或应用信用额来计算。

我认为这样的事情可能有用，但我不认为SUM表达式在case语句中正确评估，因为它只返回＆＃34; else＆＃34;条件。

select t.range as [price range], COUNT(*) as [orders]
from (
    select case
        when SUM(o.subtotal - o.discount - o.credit) between 0 and 49.99 then '0-49.99'
        when SUM(o.subtotal - o.discount - o.credit) between 50 and 99.99 then '50-99.99'
        when SUM(o.subtotal - o.discount - o.credit) between 100 and 149.99 then '100-149.99'
        when SUM(o.subtotal - o.discount - o.credit) between 150 and 199.99 then '150-199.99'
        else '200+' end as range
    from dbo.[order] o
    where o.date_placed BETWEEN '4/1/14' AND '4/30/14') t
group by t.range

我做错了什么？这是在MS SQL Server btw。

Answer 1

为您的案例陈述试用此格式

select 
    sum(case when o.subtotal - o.discount - o.credit between 0 and 49.99 then 1 else 0 end) as bucket1,
    sum(case when o.subtotal - o.discount - o.credit between 50 and 99.99 then 1 else 0 end) as bucket2,
    sum(case when o.subtotal - o.discount - o.credit between 100 and 149.99 then then 1 else 0 end) as bucket3,
    sum(case when o.subtotal - o.discount - o.credit between 150 and 199.99 then 1 else 0 end) as bucket4,
    sum(case when o.subtotal - o.discount - o.credit >= 200 then 1 else 0 end) as bucket5

Answer 2

这应该有效：

select t.range as [price range], COUNT(*) as [orders]
from (
    select case
        when (o.subtotal - o.discount - o.credit) between 0 and 49.99 then '0-49.99'
        when (o.subtotal - o.discount - o.credit) between 50 and 99.99 then '50-99.99'
        when (o.subtotal - o.discount - o.credit) between 100 and 149.99 then '100-149.99'
        when (o.subtotal - o.discount - o.credit) between 150 and 199.99 then '150-199.99'
        else '200+' end as range
    from dbo.[order] o
    where o.date_placed BETWEEN '4/1/14' AND '4/30/14') t
group by t.range

Answer 3

您也可以在一个查询中完成所有工作。实际上不需要子查询来执行此操作。

select 
    case SUM(o.subtotal - o.discount - o.credit) 
        when between 0 and 49.99 then '0-49.99'
        when between 50 and 99.99 then '50-99.99'
        when between 100 and 149.99 then '100-149.99'
        when between 150 and 199.99 then '150-199.99'
        else '200+' end 
    as PriceRange
    , COUNT(*) as [orders]
from dbo.[order] o
where o.date_placed BETWEEN '4/1/14' AND '4/30/14'
group by  case SUM(o.subtotal - o.discount - o.credit) 
    when between 0 and 49.99 then '0-49.99'
    when between 50 and 99.99 then '50-99.99'
    when between 100 and 149.99 then '100-149.99'
    when between 150 and 199.99 then '150-199.99'
    else '200+' end

用SUM选择SQL案例？

3 个答案: