SQL Server - 使用子查询中主查询的列

Question

有没有办法从主查询中实时获取列，并在子查询中使用它？

这样的事情:(在子查询中使用A.item）

SELECT item1, * 
FROM TableA A 
INNER JOIN 
(
    select * 
    from TableB B 
    where A.item = B.item
) on A.x = B.x;

好的，这是真的：

我需要修改这个现有的查询。 它以前工作过，但现在数据库发生了变化，我需要做一些修改，添加一些比较。 正如您所看到的，有很多JOINS，其中一个是子查询。 我需要从主查询（例如从表T0）到子查询的列中添加比较（如下所示： T6.UnionAll_Empresa = T0.UnionALl_Empresa ）

Select T0.UnionAll_Empresa,<STUFF>

from [UNION_ALL_BASES]..OINV T0 with (nolock)
inner join [UNION_ALL_BASES]..INV6 T1 with (nolock) on t0.DocEntry = t1.DocEntry and t0.UnionAll_Empresa = t1.UnionAll_Empresa
inner join

(
select 
t1.CompanyID,
T2.CompanyDb,
t1.OurNumber,
T6.BankCode,
T6.BankName,
T3.[Description] Situation,
T1.[Status],
T5.Descrption nomeStatus,
T1.Origin,
T1.DocEntry,
T1.DocType,
T1.ControlKey,
T1.CardCode,
T4.[Description] ContractBank,
T1.PayMethodCode,
T1.DueDate,
T1.DocDate,
T1.InstallmentID,
T1.InstallmentValue,
T1.Correction,
T1.InterestContractural,
T1.FineContract,
T1.ValueAbatment,
T1.ValueDiscount,
T1.ValueFineLate,
T1.ValueInterestDaysOfLate,
T1.OtherIncreases,
T1.ValueInWords,
T1.ValueDocument,
T1.DigitalLine,
T1.Document
from [IntegrationBank]..BillOfExchange T1 with (nolock)
    inner join [InterCompany2]..CompanyHierarchy T2 with (nolock) on T1.CompanyID = T2.ID
    left join [IntegrationBank]..BillOfExchangeSituation T3 with (nolock) on T1.Situation = T3.ID 
    inner join [IntegrationBank]..ContractBank T4 with (nolock) on T1.ContractBank = T4.ID 
    inner join [IntegrationBank]..BoeStatus T5 with (nolock) on T1.[Status] = T5.ID 
    inner join [UNION_ALL_BASES]..ODSC T6 with (nolock) on T4.BankKey = T6.AbsEntry and **T6.UnionAll_Empresa = T0.UnionALl_Empresa** --I need to do this 
where T1.[Status] <> 5 
and T2.CompanyDb = **T0.UnionAll_Empresa** --I need to do this
) TBI on (T1.DocEntry = TBI.DocEntry and T1.InstlmntID = TBI.InstallmentID and TBI.DocType = T1.ObjType )
inner join [UNION_ALL_BASES]..OCTG T2 on T0.GroupNum = T2.GroupNum and T0.UnionAll_Empresa = T2.UnionAll_Empresa
inner join [UNION_ALL_BASES]..OSLP T3 on T0.SlpCode = T3.SlpCode and T0.UnionAll_Empresa = T3.UnionAll_Empresa
where not exists (select 1
        from [UNION_ALL_BASES]..RIN1 A with (nolock) 
                inner join [UNION_ALL_BASES]..ORIN B with (nolock) on A.DocEntry = B.DocEntry and A.UnionAll_Empresa = B.UnionAll_Empresa
        where A.BaseEntry = T0.DocEntry
        and   B.SeqCode = ''1'' )

Answer 1

您可以使用OUTER APPLY

   SELECT  *
    FROM    tbl1
            OUTER APPLY ( SELECT TOP 1
                                    currency_id,
                                    SUM(taxrate) AS taxrate
                          FROM      tbl2
                          WHERE     wuptr.currency_id = tbl1.currency_id
                          GROUP BY  tbl2.currencyid
                        ) 

Answer 2

您不需要子查询：

SELECT item1, * 
FROM TableA A 
INNER JOIN 
   TableB B 
     ON A.item = B.item
     AND A.x = B.x;

我不认为这样一个场景，你需要的JOIN一个子查询与这样一个过滤器，它不会只相当于直接在外部查询引用领域。

但是，您可以在WHERE子句中引用子查询中的外部表：

SELECT <stuff>
FROM Table t
WHERE EXISTS  (SELECT 1 from TableB B 
               WHERE t.id = b.id)

编辑

对于您的实际代码，只需将JOIN条件更改为：

) TBI on (T1.DocEntry = TBI.DocEntry
          and T1.InstlmntID = TBI.InstallmentID 
          and TBI.DocType = T1.ObjType
          AND TBI.CompanyDB = T0.UnionAll_Empresa )

Answer 3

如果你想加入子查询并“实时获取一个列”/引用主查询中的一列，那么就有一个技巧可以做到这一点。

如果将子查询用作别名表，则无法访问子查询之外的表，换句话说，此SQL永远不能访问A：

...
INNER JOIN 
(
    select * 
    from TableB B 
    where A.item = B.item
) on A.x = B.x;

访问A的方式如下：

SELECT item1, * 
FROM TableA A 
INNER JOIN TableB on TableB.item = TableA.item and TableB.item in
(
    select top 1 B.Item
    from TableB B 
    where A.item = B.item
)

只要忽略“前1”部分，我只是添加了这一点，以表明可能有理由进行这样的连接。
因此，基本上如果要在子查询中引用查询中的项，只需将子查询移动到连接的ON部分，并使用IN关键字，如上所示。

Answer 4

您可以通过命名主查询和嵌套查询的表来完成此操作。 例如：

SELECT continent, name, population FROM world x
  WHERE population >= ALL
    (SELECT population FROM world y
        WHERE y.continent=x.continent
          AND population>0)

参考： http ： //sqlzoo.net/wiki/SELECT_within_SELECT_Tutorial

Answer 5

不确定为什么人们过于复杂。 @JNK是正确的，您可以将谓词移动到主查询中。 为了完整起见，我将进行演示。

子查询中有两个引用T0谓词：

T6.UnionAll_Empresa = T0.UnionAll_Empresa
T2.CompanyDb = T0.UnionAll_Empresa

第一个是表T6上的INNER JOIN谓词，第二个是WHERE子句 - 这些都是“硬”过滤器，并将过滤掉不匹配的结果（不像LEFT OUTER JOIN ，它只是设置对那个的引用）表的值为NULL ）。

好吧，既然T6.UnionAll_Empresa和T2.CompanyDb都需要对T0.UnionAll_Empresa进行过滤，那么我们可以简单地将T6上的INNER JOIN谓词更改为：

T2.CompanyDb = T6.UnionAll_Empresa

然后，我们可以删除子查询中的WHERE子句，并且可以在主查询中将此JOIN谓词添加到TBI ：

TBI.CompanyDb = T0.UnionAll_Empresa

...制作整个查询：

Select T0.UnionAll_Empresa,<STUFF>

from [UNION_ALL_BASES]..OINV T0 with (nolock)
inner join [UNION_ALL_BASES]..INV6 T1 with (nolock) on t0.DocEntry = t1.DocEntry and t0.UnionAll_Empresa = t1.UnionAll_Empresa
inner join
(
    select 
    t1.CompanyID,
    T2.CompanyDb,
    t1.OurNumber,
    T6.BankCode,
    T6.BankName,
    T3.[Description] Situation,
    T1.[Status],
    T5.Descrption nomeStatus,
    T1.Origin,
    T1.DocEntry,
    T1.DocType,
    T1.ControlKey,
    T1.CardCode,
    T4.[Description] ContractBank,
    T1.PayMethodCode,
    T1.DueDate,
    T1.DocDate,
    T1.InstallmentID,
    T1.InstallmentValue,
    T1.Correction,
    T1.InterestContractural,
    T1.FineContract,
    T1.ValueAbatment,
    T1.ValueDiscount,
    T1.ValueFineLate,
    T1.ValueInterestDaysOfLate,
    T1.OtherIncreases,
    T1.ValueInWords,
    T1.ValueDocument,
    T1.DigitalLine,
    T1.Document
    from [IntegrationBank]..BillOfExchange T1 with (nolock)
    inner join [InterCompany2]..CompanyHierarchy T2 with (nolock) on T1.CompanyID = T2.ID
    left join [IntegrationBank]..BillOfExchangeSituation T3 with (nolock) on T1.Situation = T3.ID 
    inner join [IntegrationBank]..ContractBank T4 with (nolock) on T1.ContractBank = T4.ID 
    inner join [IntegrationBank]..BoeStatus T5 with (nolock) on T1.[Status] = T5.ID 
    inner join [UNION_ALL_BASES]..ODSC T6 with (nolock) on T4.BankKey = T6.AbsEntry and T2.CompanyDb = T6.UnionAll_Empresa
    where T1.[Status] <> 5 
) TBI on (T1.DocEntry = TBI.DocEntry and T1.InstlmntID = TBI.InstallmentID and TBI.DocType = T1.ObjType and TBI.CompanyDb = T0.UnionAll_Empresa)
inner join [UNION_ALL_BASES]..OCTG T2 on T0.GroupNum = T2.GroupNum and T0.UnionAll_Empresa = T2.UnionAll_Empresa
inner join [UNION_ALL_BASES]..OSLP T3 on T0.SlpCode = T3.SlpCode and T0.UnionAll_Empresa = T3.UnionAll_Empresa
where not exists (
    select 1
    from [UNION_ALL_BASES]..RIN1 A with (nolock) 
    inner join [UNION_ALL_BASES]..ORIN B with (nolock) on A.DocEntry = B.DocEntry and A.UnionAll_Empresa = B.UnionAll_Empresa
    where A.BaseEntry = T0.DocEntry
    and B.SeqCode = ''1''
)

这完全等同于您拥有的内容，并从子查询中删除对T0任何引用。

Answer 6

您也可以使用WITH

http://msdn.microsoft.com/en-us/library/ms175972.aspx