Is it possible to compare comma delimited string in T-SQL without looping? - sql

Question

Let's say I have 2 tables where both has column called Brand. The value is comma delimited so for example if one of the table has
ACER,ASUS,HP
AMD,NVIDIA,SONY
as value. Then the other table has
HP,GIGABYTE
MICROSOFT
SAMSUNG,PHILIPS
as values.
I want to compare these table to get all matched record, in my example ACER,ASUS,HP and HP,GIGABYTE match because both has HP. Right now I'm using loop to achieve this, I'm wondering if it's possible to do this in a single query syntax.

Answer 1

You are correct in wanting to step away from the loop.
Since you are on 2012, String_Split() is off the table. However, there are any number of split/parse TVF functions in-the-wild.
Example 1 - without a TVF
Declare #T1 table (Brand varchar(50))
Insert Into #T1 values
('ACER,ASUS,HP'),
('AMD,NVIDIA,SONY')
Declare #T2 table (Brand varchar(50))
Insert Into #T2 values
('HP,GIGABYTE'),
('MICROSOFT'),
('SAMSUNG,PHILIPS')
Select Distinct
T1_Brand = A.Brand
,T2_Brand = B.Brand
From (
Select Brand,B.*
From #T1
Cross Apply (
Select RetVal = LTrim(RTrim(B.i.value('(./text())[1]', 'varchar(max)')))
From (Select x = Cast('<x>' + replace(Brand,',','</x><x>')+'</x>' as xml)) as A
Cross Apply x.nodes('x') AS B(i)
) B
) A
Join (
Select Brand,B.*
From #T2
Cross Apply (
Select RetVal = LTrim(RTrim(B.i.value('(./text())[1]', 'varchar(max)')))
From (Select x = Cast('<x>' + replace(Brand,',','</x><x>')+'</x>' as xml)) as A
Cross Apply x.nodes('x') AS B(i)
) B
) B
on A.RetVal=B.RetVal
Example 2 - with a TVF
Select Distinct
T1_Brand = A.Brand
,T2_Brand = B.Brand
From (
Select Brand,B.*
From #T1
Cross Apply [dbo].[tvf-Str-Parse](Brand,',') B
) A
Join (
Select Brand,B.*
From #T2
Cross Apply [dbo].[tvf-Str-Parse](Brand,',') B
) B
on A.RetVal=B.RetVal
Both Would Return
T1_Brand T2_Brand
ACER,ASUS,HP HP,GIGABYTE
The UDF if interested
CREATE FUNCTION [dbo].[tvf-Str-Parse] (#String varchar(max),#Delimiter varchar(10))
Returns Table
As
Return (
Select RetSeq = Row_Number() over (Order By (Select null))
,RetVal = LTrim(RTrim(B.i.value('(./text())[1]', 'varchar(max)')))
From (Select x = Cast('<x>' + replace((Select replace(#String,#Delimiter,'§§Split§§') as [*] For XML Path('')),'§§Split§§','</x><x>')+'</x>' as xml).query('.')) as A
Cross Apply x.nodes('x') AS B(i)
);
--Thanks Shnugo for making this XML safe
--Select * from [dbo].[tvf-Str-Parse]('Dog,Cat,House,Car',',')
--Select * from [dbo].[tvf-Str-Parse]('John Cappelletti was here',' ')
--Select * from [dbo].[tvf-Str-Parse]('this,is,<test>,for,< & >',',')

Answer 2

Had the same problem with comparing "," delimited strings
you can use "XML" to do that and compare the outputs and return the same/different value:
declare #TestInput nvarchar(255)
, #TestInput2 nvarchar(255)
set #TestInput = 'ACER,ASUS,HP'
set #TestInput2 = 'HP,GIGABYTE'
;WITH FirstStringSplit(S1) AS
(
SELECT CAST('<x>' + REPLACE(#TestInput,',','</x><x>') + '</x>' AS XML)
)
,SecondStringSplit(S2) AS
(
SELECT CAST('<x>' + REPLACE(#TestInput2,',','</x><x>') + '</x>' AS XML)
)
SELECT STUFF(
(
SELECT ',' + part1.value('.','nvarchar(max)')
FROM FirstStringSplit
CROSS APPLY S1.nodes('/x') AS A(part1)
WHERE part1.value('.','nvarchar(max)') IN(SELECT B.part2.value('.','nvarchar(max)')
FROM SecondStringSplit
CROSS APPLY S2.nodes('/x') AS B(part2)
)
FOR XML PATH('')
),1,1,'') as [Same Value]
Edit:
Changed 'Stuff' to 'XML'