SQL 在插入查询命令之前从其他表中获取值

Question

我想创建一个查询，允许我在将 ID 的名称添加到查询调用的所需表之前查找另一个表中显示的数字。

一个例子：

表1

ID   |name   |nameID |network |...
----------------------------------
5    |Bob    |4      |NPOW    |...
6    |Billy  |8      |BGER    |...

表2

ID   |name   |nameID |network |...
----------------------------------
3    |Stan   |2      |ERFDT   |...

表3

ID   |name   |nameID |network |...
----------------------------------
3    |Steve  |3      |FRVS    |...

Table4（我在下面插入新行的表）

ID   |name   |nameID |network |...
----------------------------------

在我的页面上，这些是我需要添加到上面 table4 的新值：

Name   |ID |network |...
------------------------
Nick   |4  |RFGH    |...
Tony   |3  |ESLO    |...
James  |2  |HUII    |...
Rusty  |3  |ERNM    |...

现在我想做的是查看哪一列 ID 等于 X 并将该名称放入 Table4。

这样做 table4 的结果应该如下所示插入后：

ID   |name   |nameFromID |network |...
--------------------------------------
1    |Nick   |Bob        |RFGH    |...
2    |Tony   |Steve      |ESLO    |...
3    |James  |Stan       |HUII    |...
4    |Rusty  |Steve      |ERNM    |...

那么 INSERT INTO Table4 查询 会是什么样子？

Answer 1

您可以使用视图、一些连接和临时表或其他带有会话范围的临时表来执行此操作。这是一个临时表方法。

将所有不同的表合并到一个可查询的表单中的视图：

CREATE VIEW vAllNames
AS
SELECT [Name], NameID FROM Table1 UNION
SELECT [Name], NameID FROM Table2 UNION
SELECT [Name], NameID FROM Table3

以上假设NameId不能在这些表中重复，所以我使用UNION而不是UNION ALL。否则，当 id 成功匹配多个表时，您需要告诉我们您希望如何解析名称。您是否希望将多条记录插入到表 4 中，只有第一个匹配项、某种连接等。

临时表，因此我们可以从中选择插入的内容，除非您想一次插入一个（您也可以使用会话范围的持久表或类似的东西来执行此操作）：

CREATE TABLE #TempDataToInsert
(
    [Name] NVARCHAR(256),
    ID INT,
    network CHAR(4)
)

创建这些后，您可以将页面中的数据直接插入TempDataToInsert。一旦您的数据在那里上演，您就可以运行最终的insert into：

INSERT INTO Table4
    ([Name], nameFromID, network) -- Assumes ID is an identity column
SELECT
    tempData.[Name], allNames.[Name], tempData.network
FROM
    #TempDataToInsert tempData
    LEFT OUTER JOIN vAllNames allNames ON tempData.ID = allNames.NameID -- assumes no match is still valid for insertions

之后您需要清理临时表，我对您的架构做了一些假设，但这应该会为您指明正确的方向。

Answer 2

CREATE TABLE #Temp0
(
    ID INT,
    [Name] VARCHAR(100),
    NameId INT,
    Network VARCHAR(100)
);

INSERT INTO #Temp0
(
    ID,
    Name,
    NameId,
    Network
)
VALUES
(5, 'Bob', 4, 'NPOW'),
(6, 'Billy', 8, 'BGER');

CREATE TABLE #Temp1
(
    ID INT,
    [Name] VARCHAR(100),
    NameId INT,
    Network VARCHAR(100)
);
INSERT INTO #Temp1
(
    ID,
    Name,
    NameId,
    Network
)
VALUES
(3, 'Stan', 2, 'ERFDT');
CREATE TABLE #Temp2
(
    ID INT,
    [Name] VARCHAR(100),
    NameId INT,
    Network VARCHAR(100)
);
INSERT INTO #Temp2
(
    ID,
    Name,
    NameId,
    Network
)
VALUES
(3, 'Steve', 3, 'FRVS');
SELECT *
INTO #Temp
FROM
(
    SELECT [Name],
           NameId
    FROM #Temp0
    UNION
    SELECT [Name],
           NameId
    FROM #Temp1
    UNION
    SELECT [Name],
           NameId
    FROM #Temp2
) AS Temp;



CREATE TABLE #Temp3
(
    [Name] VARCHAR(100),
    Id INT,
    Network VARCHAR(100)
);

INSERT INTO #Temp3
(
    Name,
    Id,
    Network
)
VALUES
('Nick', 4, 'RFGH'),
('Tony', 3, 'ESLO'),
('James', 2, 'HUII'),
('RUSTY', 3, 'ERNM');


CREATE TABLE #Table4
(
    ID INT IDENTITY(1, 1),
    [Name] VARCHAR(100),
    NameFormId VARCHAR(100),
    Network VARCHAR(100)
);

INSERT INTO #Table4
SELECT T2.Name,
       T1.Name,
       T2.Network
FROM #Temp T1
    JOIN #Temp3 T2
        ON T1.NameId = T2.Id;

SELECT *
FROM #Table4;

Answer 3

以下代码演示了如何在表之间匹配NameId 上的数据。它假定添加的Names 是唯一的。如果输入表之间有多个NameId 匹配，则优先考虑最早的匹配。单个输入表中的多个NameId 匹配优先考虑最低的Id。

-- Sample data.
declare @Table1 as Table ( Id Int, Name VarChar(10), NameId Int, Network VarChar(10) );
insert into @Table1 ( Id, Name, NameId, Network ) values
  ( 5, 'Bob', 4, 'NPOW' ), ( 6, 'Billy', 8, 'BGER' );
select * from @Table1;

declare @Table2 as Table ( Id Int, Name VarChar(10), NameId Int, Network VarChar(10) );
insert into @Table2( Id, Name, NameId, Network ) values
  ( 3, 'Stan', 2, 'ERFDT' );
select * from @Table2;

declare @Table3 as Table ( Id Int, Name VarChar(10), NameId Int, Network VarChar(10) );
insert into @Table3 ( Id, Name, NameId, Network ) values
  ( 3, 'Steve', 3, 'FRVS' ),
  ( 4, 'Steven', 3, 'FRVS' ), -- Note duplicate   NameId   value.
  ( 9, 'Stanley', 2, 'VOOT' ); -- Note duplicate   NameId   value.
select * from @Table3;

declare @ValuesToAdd as Table ( Name VarChar(10), NameId Int, Network VarChar(10) );
insert into @ValuesToAdd ( Name, NameId, Network ) values
  ( 'Nick', 4, 'RFGH' ), ( 'Tony', 3, 'ESLO' ),
  ( 'James', 2, 'HUII' ), ( 'Rusty', 3, 'ERNM' );
select * from @ValuesToAdd;

-- Process the data.
declare @Table4 as Table ( Id Int Identity, Name VarChar(10), NameId Int,
  NameFromId VarChar(10), Network VarChar(10) );
-- Demonstrate the matching.
select Name, NameId, NameFromId, Network
  from (
    select VTA.Name, VTA.NameId, N.Name as NameFromId, VTA.Network,
      Row_Number() over ( partition by VTA.Name order by NameRank, Id ) as RN
      from @ValuesToAdd as VTA inner join ( -- Use   left outer join   if there might not be a match on   NameId .
        select Id, Name, NameId, 1 as NameRank from @Table1 union all
        select Id, Name, NameId, 2 from @Table2 union all
        select Id, Name, NameId, 3 from @Table3 ) as N on N.NameId = VTA.NameId ) as PH
  --where RN = 1; -- Pick the match from the earliest table.
-- Insert the results.
insert into @Table4
  select Name, NameId, NameFromId, Network
    from (
      select VTA.Name, VTA.NameId, N.Name as NameFromId, VTA.Network,
        Row_Number() over ( partition by VTA.Name order by NameRank, Id ) as RN
        from @ValuesToAdd as VTA inner join ( -- Use   left outer join   if there might not be a match on   NameId .
          select Id, Name, NameId, 1 as NameRank from @Table1 union all
          select Id, Name, NameId, 2 from @Table2 union all
          select Id, Name, NameId, 3 from @Table3 ) as N on N.NameId = VTA.NameId ) as PH
    where RN = 1; -- Pick the match from the earliest table.
select * from @Table4;