如何运行基于查询结果的子查询 SQL

Question

我有 2 个问题想运行。这里的思路是通过事务"type"运行查询事务table。基于这些结果，我想运行另一个查询以查看基于特定类型的客户上次交易以查看服务 ID 是否相同。如果不一样，我想将其标记为 "upgraded"

这是根据交易类型从交易 table 中提取结果的初始查询：

Select customerid, serviceid
from Transactions
where (dtcreated > @startdate and dtcreated < @enddate) and (transactiontype = 'Cust Save')

这个输出是：

Customerid          ServiceID
    1                   11
    2                   21
    3                   21
    4                   11
    5                   12
    6                   11

接下来我想做的是运行这个查询，匹配 customerID 以查看客户最后一次收费是什么：

Select serviceID, MAx(dtcreated) as MostRecent
From Transactions
Where (transactiontype = 'Cust Purchase')
Group By serviceID

我结合这两个查询的最终输出是：

Customerid          ServiceID          Last Purchase      Upgraded?
    1                   11                  11               No
    2                   21                  11               Yes
    3                   21                  12               Yes
    4                   11                  10               Yes
    5                   12                  12               No
    6                   11                  11               No

我认为这可能有用，但它并不能完全满足我的需求。 returns结果太多，所以查询显然不正确。:

Select serviceID, MAx(dtcreated) as MostRecent
From Transactions
WHERE     Where (transactiontype = 'Cust Purchase') AND EXISTS
                          (Select customerid, serviceid
                           from Transactions
                           where (dtcreated > @startdate and dtcreated < @enddate) and (transactiontype = 'Cust Save'))
GROUP BY serviceid

Answer 1

我想你需要这样的东西。这里 t1 为您提供了每个客户创建的最大 dt； t2 包含给定日期范围内的所有交易； t3 为您提供每个客户的最后一次购买。

select 

t1.customerid,
t3.serviceid as Last_Purchase_ServiceID, 
t1.dtcreated as Last_Purchase_DateCreated, 

t2.ServiceID as Current_Purchase_ServiceID,
t2.dtcreated as Current_Purchase_DateCreated 

from

(
    select customerid, max(dtcreated) as dtcreated
    from
    Transactions
    group by customerid
) 

t1

join 

(

select customerid, serviceid, dtcreated
from Transactions
where (dtcreated > @startdate and dtcreated < @enddate) and (transactiontype = 'Cust Save')

) t2 on t1.customerid = t2.customerid

join 

Transactions t3 on t1.customerid = t3.customerid and t1.dtcreated = t3.dtcreated

Answer 2

如果我正确理解这些要求，您可以使用 ROW_NUMBER 来确定每个客户 ID 的最新记录。然后您可以将其加入到事务 table 以确定 ServiceID 中是否存在匹配项：

SELECT  r.CustomerID,
        t.ServiceID,
        t.dtCreated,
        Upgraded = CASE WHEN t.ServiceID = cp.ServiceID THEN 0 ELSE 1 END
FROM    Transactions AS t
        INNER JOIN
        (   SELECT  CustomerID,
                    ServiceID,
                    dtCreated,
                    RowNumber = ROW_NUMBER() OVER(PARTITION BY CustomerID ORDER BY dtCreated DESC)
            FROM    Transactions
            WHERE   transactiontype = 'Cust Purchase'
        ) AS cp
            ON cp.CustomerID = t.CustomerID
            AND cp.RowNumber = 1
WHERE   t.dtcreated > @startdate 
AND     t.dtcreated < @enddate
AND     t.transactiontype = 'Cust Save'

Answer 3

尝试 OUTER APPLY:

Select t.customerid, t.serviceid, o.MostRecent
from Transactions t
OUTER APPLY (
             Select  MAx(dtcreated) as MostRecent
             From Transactions
             Where transactiontype = 'Cust Purchase' and Customerid = t.Customerid --And ServiceID = t.ServiceID
            ) o
where (t.dtcreated > @startdate and t.dtcreated < @enddate) and (t.transactiontype = 'Cust Save')

如何运行基于查询结果的子查询 SQL

How to run a subquery based on results of a query SQL

sql

sql-server

sql-server-2008

sql-server-2005

如何 运行 基于查询结果的子查询 SQL

How to run a subquery based on results of a query SQL

sql

sql-server

sql-server-2008

sql-server-2005

如何运行基于查询结果的子查询 SQL