如何在不使用聚合函数的情况下使用 Pivot

Question

我使用的是 MS Sql2008，

     Table1: Plan.Plan
     Table2: Plan.PlanFeature
     Table3:Plan.PlanDetails

    Plan.Plan

    PlanID_PK    PlanName  AnnualPrice  MonthlyPrice

  1                   Plan1            Free              Free
  2                   Plan2            $50.00          $4.99
  3                   Plan3            $100.00        $9.99

Plan.PlanFeature

PlanFeatureID_PK    FeatureName
- - - - - - - - - - - - - - - - - - - - - - - - - - - 
        1                           Feature1
        2                           Feature2
        3                           Feature3
        4                           Feature4


Plan.PlanDetails

PlanDetailsID_PK    PlanID_FK    PlanFeatureID_FK    Quantity     Quantity_Type
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - -
             1                        1                   1                                0               Included
             2                        1                   2                                0               Unlimited
             3                        1                   3                                2               None
             4                        1                   4                                0               Unlimited
             5                        2                   1                                0               Included
             6                        2                   2                                0               Unlimited
             7                        2                   3                                20               None
             8                        2                   4                                0               Unlimited
             9                        3                   1                                0               Included
             10                      3                   2                                0               Unlimited
             11                      3                   3                                >20               None
             12                      3                   4                                0               Unlimited




Output :

FeatureName     Plan1          Plan2         Plan3  
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
Feature1          Included      Included      Included
Feature2          Unlimited     Unlimited    Unlimited
Feature3              2                    20                >20
Feature4          Unlimited     Unlimited     Unlimited
AnnualPrice     Free             $50.00           $100.00
MonthlyPrice   Free             $4.99              $9.99

所以我们开始吧，为了将行转换为列，我使用了 COALESCE 和 Pivot

这里是我正在尝试的存储过程，

DECLARE @cols NVARCHAR(2000)
DECLARE @SubjectQuery NVARCHAR(MAX)
SELECT  @cols = COALESCE(@cols + ',[' + PlanNames + ']',
                         '[' + PlanNames + ']')
FROM    Plans.Plans
ORDER BY PlanNames
SET @SubjectQuery = 'SELECT FeatureName, ' + @cols + '
FROM 
(select p.PlanId_PK, p.PlanNames,pf.FeatureName,pd.Quantity from Plans.PlanDetails pd 
join Plans.Plans p on pd.PlanId_FK=p.PlanId_PK 
join Plans.PlanFeatures pf on pd.PlanFeatureId_FK=pf.PlanFeatureId_PK  ) S
PIVOT
(
Count(Quantity) --Dont know which aggregate functions i have to use here according to my output
FOR PlanNames IN
(' + @cols + ')) AS pvt'
exec @SubjectQuery

对于数量，我必须检查像这样MAX(CASE WHEN pd.Quantity = '0' THEN pd.Quantity_Type)as Quantity 这样的条件，如果数量值为 0，那么我必须显示 Quantity_type 值

根据我的输出，在枢轴块内部不知道我必须使用哪个聚合函数，你能解决这个问题吗？

Answer 1

根据您的示例数据和期望输出，我认为您将希望在子查询中使用 case，在 pivot 之前：

DECLARE @cols NVARCHAR(2000)
DECLARE @SubjectQuery NVARCHAR(MAX)
SELECT  @cols = COALESCE(@cols + ',[' + PlanName + ']',
                         '[' + PlanName + ']')
FROM    [Plans]
ORDER BY PlanName


SET @SubjectQuery 
   = 'SELECT FeatureName, ' + @cols + '
      FROM 
      (
        select p.PlanName,
          pf.FeatureName,
              MAX(CASE WHEN pd.Quantity = ''0'' THEN pd.Quantity_Type else quantity end)as Quantity
        from PlanDetails pd 
        join [Plans] p 
          on pd.PlanId_FK=p.PlanId_PK 
        join PlanFeature pf 
          on pd.PlanFeatureId_FK=pf.PlanFeatureId_PK  
        group by p.PlanName, pf.FeatureName
      ) S
      PIVOT
      (
        max(Quantity)
        FOR PlanName IN (' + @cols + ')
      ) AS pvt'

exec(@SubjectQuery);

见SQL Fiddle with Demo。

结果是：

| FEATURENAME |     PLAN1 |     PLAN2 |     PLAN3 |
---------------------------------------------------
|    Feature1 |  Included |  Included |  Included |
|    Feature2 | Unlimited | Unlimited | Unlimited |
|    Feature3 |         2 |        20 |       >20 |
|    Feature4 | Unlimited | Unlimited | Unlimited |

编辑，如果您需要年度价格和每月价格，则需要合并unpivot 和pivot 函数：

DECLARE @cols NVARCHAR(2000)
DECLARE @SubjectQuery NVARCHAR(MAX)
SELECT  @cols = COALESCE(@cols + ',[' + PlanName + ']',
                         '[' + PlanName + ']')
FROM    [Plans]
ORDER BY PlanName


SET @SubjectQuery 
   = 'SELECT FeatureName,'+@cols+'
      FROM 
      (
          select PlanName, FeatureName, 
              MAX(CASE WHEN Quantity = ''0'' THEN Quantity_Type else quantity end)as Quantity,
              SortOrder
          from
          (
              select p.PlanName, pf.FeatureName, pd.Quantity, pd.Quantity_Type, 1 Sortorder
              from PlanDetails pd 
              join [Plans] p 
                on pd.PlanId_FK=p.PlanId_PK 
              join PlanFeature pf 
                on pd.PlanFeatureId_FK=pf.PlanFeatureId_PK  
              union all
              select PlanName, col, ''0'', value, 2 SortOrder
              from
              (
                  select PlanID_PK, PlanName,
                      AnnualPrice, 
                      cast(MonthlyPrice as varchar(6)) MonthlyPrice
                  from plans
              ) src
              unpivot
              (
                  value
                  for col in (annualprice, monthlyprice)
              ) unpiv
          ) pl
          group by PlanName, FeatureName, SortOrder
      ) d
      PIVOT
      (
          max(Quantity)
          FOR PlanName IN ('+@cols+')
      ) AS pvt
      order by SortOrder'

exec(@SubjectQuery);

见SQL Fiddle with Demo

结果：

|  FEATURENAME |     PLAN1 |     PLAN2 |     PLAN3 |
----------------------------------------------------
|     Feature1 |  Included |  Included |  Included |
|     Feature2 | Unlimited | Unlimited | Unlimited |
|     Feature3 |         2 |        20 |       >20 |
|     Feature4 | Unlimited | Unlimited | Unlimited |
|  AnnualPrice |      Free |     50.00 |    100.00 |
| MonthlyPrice |      Free |      4.99 |      9.99 |