动态创建sql列

我有一桌顾客

Customer ID        Name         
   1               John        
   2               Lewis        
   3               Mary         

我有另一张桌子，顾客服务

 TypeID           Description
   1                Bronze
   2                Silver
   3                Gold
   4               Platinum
   5               AnotherOne

最后一张桌子呢

 RewardID          TypeID          CustomerID
    1                1                 1
    2                1                 1
    3                2                 1
    4                2                 2

customerTypes表是动态的，其中许多类型都可以添加和删除。基本上，我只希望动态生成列，每个列中都有一个计数，比如

CustomerName        Bronze        Silver     Gold      Platinum     AnotherOne    total
   John               2             1         0           0             0           3
   Lewis              0             1         0           0             0           1
 Grand TOTAL          2             2         0           0             0           4

我说过的问题是，类型是动态的，客户是动态的，所以我需要根据系统中的类型使列是动态的

我已经在DataGridView中标记了c，因为我需要它

提前感谢

您需要为此使用透视功能。如果列数已知，则可以对值进行硬编码：

select name, [Bronze], [Silver], [Gold], [Platinum], [AnotherOne]
from
(
  select c.name,
    cr.description,
    r.typeid
  from customers c
  left join rewards r
    on c.id = r.customerid
  left join customerrewards cr
    on r.typeid = cr.typeid
) x
pivot
(
  count(typeid)
  for description in ([Bronze], [Silver], [Gold], [Platinum], [AnotherOne])
) p;

看

现在，如果列数未知，则可以使用动态SQL来透视：

看

如果需要包含总计列，则可以使用汇总：

动态版本：

---

这看起来像一个支点。我已经做了一些，但我无法从记忆中键入一个。也许数据库中的视图是通过在SQL端旋转数据创建的？如果需要在SQL中这样做，您可能需要动态透视。看，例如，但这不是一个真正干净的解决方案。如果您可以等待将数据输入C，您可以使用LINQ来完成这项工作。这些看起来确实很复杂！感谢您的评论，我将研究Pivot，但如果有人有一个简单的解决方案，请放心。您可能有一个SQL注入缺陷/可用性缺陷：=STUFFSELECT'，Sum'+QUOTENAMEdescription+'as'+描述应该是：=STUFFSELECT'，Sum'+QUOTENAMEdescription+'as'+QUOTENAMEdescription，否则，那是一篇很棒的帖子@是的，你是对的。我更新了我的代码。谢谢你接电话。

DECLARE @cols AS NVARCHAR(MAX),
    @query  AS NVARCHAR(MAX)

select @cols = STUFF((SELECT ',' + QUOTENAME(description) 
                    from customerrewards
                    group by description, typeid
                    order by typeid
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,1,'')

set @query = 'SELECT name,' + @cols + ' from 
             (
                select c.name,
                  cr.description,
                  r.typeid
                from customers c
                left join rewards r
                  on c.id = r.customerid
                left join customerrewards cr
                  on r.typeid = cr.typeid
            ) x
            pivot 
            (
                count(typeid)
                for description in (' + @cols + ')
            ) p '

execute(@query)

select name, sum([Bronze]) Bronze, sum([Silver]) Silver, 
  sum([Gold]) Gold, sum([Platinum]) Platinum, sum([AnotherOne]) AnotherOne
from 
(
  select name, [Bronze], [Silver], [Gold], [Platinum], [AnotherOne]
  from
  (
    select c.name,
      cr.description,
      r.typeid
    from customers c
    left join rewards r
      on c.id = r.customerid
    left join customerrewards cr
      on r.typeid = cr.typeid
  ) x
  pivot
  (
    count(typeid)
    for description in ([Bronze], [Silver], [Gold], [Platinum], [AnotherOne])
  ) p
) x
group by name with rollup

DECLARE @cols AS NVARCHAR(MAX),
    @colsRollup AS NVARCHAR(MAX),
    @query  AS NVARCHAR(MAX)

select @cols = STUFF((SELECT ',' + QUOTENAME(description) 
                    from customerrewards
                    group by description, typeid
                    order by typeid
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,1,'')

select @colsRollup 
      = STUFF((SELECT ', Sum(' + QUOTENAME(description) + ') as '+ QUOTENAME(description)
                    from customerrewards
                    group by description, typeid
                    order by typeid
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,1,'')


set @query 
          = 'SELECT name, '+ @colsRollup + '
             FROM
             (
                SELECT name,' + @cols + ' from 
                 (
                    select c.name,
                      cr.description,
                      r.typeid
                    from customers c
                    left join rewards r
                      on c.id = r.customerid
                    left join customerrewards cr
                      on r.typeid = cr.typeid
                ) x
                pivot 
                (
                    count(typeid)
                    for description in (' + @cols + ')
                ) p 
              ) x1
              GROUP BY name with ROLLUP'

execute(@query)