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

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迷失自我
迷失自我 2021-02-11 05:34

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  
         


        
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  • 2021-02-11 06:02

    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,< & >',',')
    
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  • 2021-02-11 06:02

    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'

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