使用内连接

时间:2016-09-22 12:26:59

标签: sql sql-server sql-server-2008 inner-join

CategoryTable

   Code   Name
    1      Food
    2      Non-Food

现有表格包含类别列表,例如,我有两个只有食物和非食物

作为挑战,我正在为租户分配类别或类别(多次转让,因为有些租户被归类为食品和非食品)。我曾经将Tenant和Code插入到创建此输出的新表中

TenantAssignTable

Tenant    Code   
Tenant1   1,2    
Tenant2   1   

我需要做的是将TenantAssingTable加载到包含CategoryCode名称的gridview,就像这样

所需输出

   Tenant    CCode    Name
    Tenant1   1,2    Food,Non-Food
    Tenant2   1      Food

我在代码中使用了内部联接,但这是有限的,因为我在代码列中有一串组合代码。

Select a.tenant, a.ccode, b.name
from TenantAssignTable a inner join CategoryTable b
on a.CCode = b.code

无论如何都要实现这种输出吗?我知道这在SQL编码中是不寻常的,但这就是所需的输出所关注的挑战,以及为单个租户多次分配类别的需求。

提前致谢!

3 个答案:

答案 0 :(得分:2)

想想简单;

您可以使用LIKEXML PATH

DECLARE @CategoryTable TABLE (Code VARCHAR(50), Name VARCHAR(50))
INSERT INTO @CategoryTable
VALUES  
('1', 'Food'),
('2', 'Non-Food')

DECLARE @TenantAssignTable TABLE (Tenant VARCHAR(50), Code VARCHAR(50))
INSERT INTO @TenantAssignTable
VALUES  
('Tenant1', '1,2'),
('Tenant2', '1')

SELECT
    T.Tenant ,
    T.Code,
    STUFF(
        (SELECT
            ',' + C.Name
        FROM
            @CategoryTable C
        WHERE
            ',' + REPLACE(T.Code, ' ', '') + ',' LIKE '%,' + C.Code + ',%'
        FOR XML PATH('')
    ), 1, 1, '') A
FROM
    @TenantAssignTable T

结果:

Tenant          Code         A
--------------- ------------ ---------------
Tenant1         1,2          Food,Non-Food
Tenant2         1            Food   

答案 1 :(得分:0)

您可以使用一些XML转换:

DECLARE @x xml

SELECT @x = (
    SELECT CAST('<t name="'+a.tenant +'"><a>'+REPLACE(a.code,',','</a><a>') +'</a></t>' as xml)
    FROM TenantAssignTable a 
    FOR XML PATH('')
)

;WITH cte AS (
SELECT  t.v.value('../@name','nvarchar(max)') as Tenant,
        t.v.value('.','int') as CCode,
        ct.Name
FROM @x.nodes('/t/a') as t(v)
INNER JOIN CategoryTable ct
    ON ct.Code = t.v.value('.','int')
)

SELECT DISTINCT
            c.Tenant,
            STUFF((SELECT ','+CAST(CCode as nvarchar(10))
            FROM cte
            WHERE c.Tenant = Tenant
            FOR XML PATH('')
            ),1,1,'') as CCode,
            STUFF((SELECT ','+Name
            FROM cte
            WHERE c.Tenant = Tenant
            FOR XML PATH('')
            ),1,1,'') as Name
FROM cte c

输出:

Tenant  CCode   Name
Tenant1 1,2     Food,Non-Food
Tenant2 1       Food

第一部分(定义{{​​1}}变量)将使您的表成为这种XML:

@x

然后在CTE部分,我们将XML与类别表联系起来。毕竟在FOR XML PATH的帮助下从CTE获取数据。

答案 2 :(得分:0)

创建如下所示的函数,该函数从分离的值

返回表
CREATE FUNCTION [dbo].[fnSplit]
(
    @String NVARCHAR(4000),
    @Delimiter NCHAR(1)
)
RETURNS TABLE
AS
RETURN
(
    WITH Split(stpos,endpos)
    AS(
        SELECT 0 AS stpos, CHARINDEX(@Delimiter,@String) AS endpos
        UNION ALL
        SELECT endpos+1, CHARINDEX(@Delimiter,@String,endpos+1)
            FROM Split
            WHERE endpos > 0
    )
    SELECT 'Id' = ROW_NUMBER() OVER (ORDER BY (SELECT 1)),
        'Data' = SUBSTRING(@String,stpos,COALESCE(NULLIF(endpos,0),LEN(@String)+1)-stpos)
    FROM Split
)

创建如下所示的函数,返回逗号分隔名称

CREATE FUNCTION [dbo].[GetCommaSeperatedCategory]
(
    @Codes VARCHAR(50)
)
RETURNS VARCHAR(5000)
AS
BEGIN
    -- Declare the return variable here
    DECLARE @Categories VARCHAR(5000)

    SELECT @Categories= STUFF
                        (
                                (SELECT ',' + convert(varchar(10), Name, 120)
                                FROM Category
                                WHERE Code IN (SELECT Id FROM [dbo].[fnSplit] (@Codes,',') )
                                ORDER BY Code
                                FOR XML PATH (''))
                        , 1, 1, '') 

    RETURN @Categories

END

和最后:

SELECT
    Tenant,
    Code,
    (SELECT [dbo].[GetCommaSeperatedCategory] (Code)) AS Name
FROM TblTenant