SQL Server-选择每种组合

Question

我们在下面有两个表，我正在尝试编写一个查询，该查询将为团队中的每个人选择“每个人都购买”。 例如，它应该显示PersonA与PurchaseID 1和2相关联，因为它们与TeamA在同一团队中。

这可能吗？ 我以为交叉连接会起作用，但是似乎带来了太多的专栏。 我正在运行SQL Server。

谢谢

购买

| PurchaseID    | PersonID  |
|------------   |---------- |
| 1             | TeamA     |
| 2             | TeamA     |
| 3             | PersonA   |
| 4             | PersonB   |
| 5             | TeamB     |

队伍

| TeamID    | PersonID  |
|--------   |---------- |
| 1         | PersonA   |
| 1         | TeamA     |
| 1         | PersonC   |
| 2         | PersonB   |
| 2         | TeamB     |

预期结果（在PurchaseID 1上过滤时）：

| PurchaseID    | PersonID  |
|------------   |---------- |
| 1             | TeamA     |
| 1             | PersonA   |
| 1             | PersonC   |

Answer 1

您的数据结构有点奇怪，但是我想我知道您想要什么。

如果PersonA进行了购买，而PersonA在TeamA上，则应该显示TeamA上的每个人都与购买相关，对吗？ 就像“我为团队购买了这些甜甜圈，所以团队中的每个人都得到了甜甜圈”。

您可能想要的是，要在PersonID上加入Purchase to Team。 但是，然后使用内联表值函数中的CROSS APPLY函数返回与“当前行”中的人员在同一团队中的所有人员。

我使用两个常见的表表达式来表示您的表，因此可以运行它。 您只需要SELECT部分​​：

with Purchases as (
      select 1 as PurchaseID, 'TeamA'   as PersonID
union select 2 as PurchaseID, 'TeamA'   as PersonID
union select 3 as PurchaseID, 'PersonA' as PersonID
union select 4 as PurchaseID, 'PersonB' as PersonID
union select 5 as PurchaseID, 'TeamB'   as PersonID
)
, Teams as (
      select 1 as TeamID, 'PersonA' as PersonID
union select 1 as TeamID, 'TeamA'   as PersonID
union select 1 as TeamID, 'PersonC' as PersonID
union select 2 as TeamID, 'PersonB' as PersonID
union select 2 as TeamID, 'TeamB'   as PersonID
)
select Purchases.PurchaseID
     , EveryTeamMember.PersonID
  from Purchases
  join Teams
    on Teams.PersonID = Purchases.PersonID
cross apply (
             select PersonID
               from Teams InnerTable
              where InnerTable.TeamID = Teams.TeamID
            ) as EveryTeamMember
where Purchases.PurchaseID = 1

Answer 2

如果您要在PersonID以Team开头时获取所有团队人员，那么我认为您应该对以Team和UNION （不是UNION ALL）单人购买开始的所有PersonID进行交叉申请：

DECLARE @Purchases TABLE (
    PurchaseID INT,
    PersonID Varchar(50)
)
INSERT INTO @Purchases(PersonID,PurchaseID) VALUES ('TeamA', 1);
INSERT INTO @Purchases(PersonID,PurchaseID) VALUES ('TeamA', 2);
INSERT INTO @Purchases(PersonID,PurchaseID) VALUES ('PersonA', 3);
INSERT INTO @Purchases(PersonID,PurchaseID) VALUES ('PersonB', 4);
INSERT INTO @Purchases(PersonID,PurchaseID) VALUES ('TeamB', 5);



DECLARE @Teams TABLE (
    TeamID INT,
    PersonID Varchar(50)
)
INSERT INTO @Teams(PersonID,TeamID) VALUES ('PersonA', 1);
INSERT INTO @Teams(PersonID,TeamID) VALUES ('TeamA', 1);
INSERT INTO @Teams(PersonID,TeamID) VALUES ('PersonC', 1);
INSERT INTO @Teams(PersonID,TeamID) VALUES ('PersonB', 2);
INSERT INTO @Teams(PersonID,TeamID) VALUES ('TeamB', 2);


SELECT T1.PurchaseID,TeamPersons.PersonID
FROM @Purchases T1
INNER JOIN @Teams T2
ON T2.PersonID = T1.PersonID AND T1.PersonID LIKE'Team%'
CROSS APPLY (
             SELECT PersonID
               FROM @Teams T3
              WHERE T3.TeamID = T2.TeamID
            ) AS TeamPersons

UNION 

SELECT T1.PurchaseID
     , T1.PersonID
  FROM @Purchases T1
WHERE T1.PersonID NOT LIKE 'Team%'

结果