SQL Query using inner join - sql

Question

CategoryTable
Code Name
1 Food
2 Non-Food
Existing Table Consists list of category, as for example, I have two only Food and Non-Food
As challenge, I am assigning tenants with category or categories (multiple assignment, as there are tenants which are categorized as food and non-food). I i used to insert Tenant and Code to a new table creating this output
TenantAssignTable
Tenant Code
Tenant1 1,2
Tenant2 1
What I need to do, is to load the TenantAssingTable to gridview consisting the Name of the CategoryCode too like this
Desired Output
Tenant CCode Name
Tenant1 1,2 Food,Non-Food
Tenant2 1 Food
I used inner join in my code, but this is limited as I have a string of combined code in Code column.
Select a.tenant, a.ccode, b.name
from TenantAssignTable a inner join CategoryTable b
on a.CCode = b.code
Is there anyway to achieve this kind of output? I know that this is unusual in SQL coding but this is what is challenge as what the desired output is concerned and needs which is to have a multiple assignment of category to a single tenant.
Thanks in advance!

Answer 1

Think simple;
You can with LIKE and XML 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
Result:
Tenant Code A
--------------- ------------ ---------------
Tenant1 1,2 Food,Non-Food
Tenant2 1 Food

Answer 2

You can use some XML transformations:
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
Output:
Tenant CCode Name
Tenant1 1,2 Food,Non-Food
Tenant2 1 Food
The first part (defining #x variable) will bring your table to this kind of XML:
<t name="Tenant1">
<a>1</a>
<a>2</a>
</t>
<t name="Tenant2">
<a>1</a>
</t>
Then in CTE part we join XML with table of categories. And after all get data from CTE with the help of FOR XML PATH.

Answer 3

Create Function as below which return Table from separated Value
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
)
Create Function as below which return comma separated Name
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
AND Last:
SELECT
Tenant,
Code,
(SELECT [dbo].[GetCommaSeperatedCategory] (Code)) AS Name
FROM TblTenant