Turning a Comma Separated string into individual r

Question

I have a SQL Table like this:

| SomeID         | OtherID     | Data
+----------------+-------------+-------------------
| abcdef-.....   | cdef123-... | 18,20,22
| abcdef-.....   | 4554a24-... | 17,19
| 987654-.....   | 12324a2-... | 13,19,20

is there a query where I can perform a query like SELECT OtherID, SplitData WHERE SomeID = 'abcdef-.......' that returns individual rows, like this:

| OtherID     | SplitData
+-------------+-------------------
| cdef123-... | 18
| cdef123-... | 20
| cdef123-... | 22
| 4554a24-... | 17
| 4554a24-... | 19

Basically split my data at the comma into individual rows?

I am aware that storing a comma-separated string into a relational database sounds dumb, but the normal use case in the consumer application makes that really helpful.

I don't want to do the split in the application as I need paging, so I wanted to explore options before refactoring the whole app.

It's SQL Server 2008 (non-R2).

Answer 1

Below works on sql server 2008

select *, ROW_NUMBER() OVER(order by items) as row# 
from 
( select 134 myColumn1, 34 myColumn2, 'd,c,k,e,f,g,h,a' comaSeperatedColumn) myTable
    cross apply 
SPLIT (rtrim(comaSeperatedColumn), ',') splitedTable -- gives 'items'  column 

Will get all Cartesian product with the origin table columns plus "items" of split table.

Answer 2

Nice to see that it have been solved in the 2016 version, but for all of those that is not on that, here are two generalized and simplified versions of the methods above.

The XML-method is shorter, but of course requires the string to allow for the xml-trick (no 'bad' chars.)

XML-Method:

create function dbo.splitString(@input Varchar(max), @Splitter VarChar(99)) returns table as
Return
    SELECT Split.a.value('.', 'VARCHAR(max)') AS Data FROM
    ( SELECT CAST ('<M>' + REPLACE(@input, @Splitter, '</M><M>') + '</M>' AS XML) AS Data 
    ) AS A CROSS APPLY Data.nodes ('/M') AS Split(a); 

Recursive method:

create function dbo.splitString(@input Varchar(max), @Splitter Varchar(99)) returns table as
Return
  with tmp (DataItem, ix) as
   ( select @input  , CHARINDEX('',@Input)  --Recu. start, ignored val to get the types right
     union all
     select Substring(@input, ix+1,ix2-ix-1), ix2
     from (Select *, CHARINDEX(@Splitter,@Input+@Splitter,ix+1) ix2 from tmp) x where ix2<>0
   ) select DataItem from tmp where ix<>0

Function in action

Create table TEST_X (A int, CSV Varchar(100));
Insert into test_x select 1, 'A,B';
Insert into test_x select 2, 'C,D';

Select A,data from TEST_X x cross apply dbo.splitString(x.CSV,',') Y;

Drop table TEST_X

XML-METHOD 2: Unicode Friendly

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Answer 3

Function

CREATE FUNCTION dbo.SplitToRows (@column varchar(100), @separator varchar(10))
RETURNS @rtnTable TABLE
  (
  ID int identity(1,1),
  ColumnA varchar(max)
  )
 AS
BEGIN
    DECLARE @position int = 0
    DECLARE @endAt int = 0
    DECLARE @tempString varchar(100)

    set @column = ltrim(rtrim(@column))

    WHILE @position<=len(@column)
    BEGIN       
        set @endAt = CHARINDEX(@separator,@column,@position)
            if(@endAt=0)
            begin
            Insert into @rtnTable(ColumnA) Select substring(@column,@position,len(@column)-@position)
            break;
            end
        set @tempString = substring(ltrim(rtrim(@column)),@position,@endAt-@position)

        Insert into @rtnTable(ColumnA) select @tempString
        set @position=@endAt+1;
    END
    return
END

Use case

select * from dbo.SplitToRows('T14; p226.0001; eee; 3554;', ';')

Or just a select with multiple result set

DECLARE @column varchar(max)= '1234; 4748;abcde; 324432'
DECLARE @separator varchar(10) = ';'
DECLARE @position int = 0
DECLARE @endAt int = 0
DECLARE @tempString varchar(100)

set @column = ltrim(rtrim(@column))

WHILE @position<=len(@column)
BEGIN       
    set @endAt = CHARINDEX(@separator,@column,@position)
        if(@endAt=0)
        begin
        Select substring(@column,@position,len(@column)-@position)
        break;
        end
    set @tempString = substring(ltrim(rtrim(@column)),@position,@endAt-@position)

    select @tempString
    set @position=@endAt+1;
END

Answer 4

Please refer below TSQL. STRING_SPLIT function is available only under compatibility level 130 and above.

TSQL:

DECLARE @stringValue NVARCHAR(400) = 'red,blue,green,yellow,black'  
DECLARE @separator CHAR = ','

SELECT [value]  As Colour
FROM STRING_SPLIT(@stringValue, @separator); 

RESULT:

Colour

red blue green yellow black

Answer 5

When using this approach you have to make sure that none of your values contains something that would be illegal XML – user1151923

I always use the XML method. Make sure you use VALID XML. I have two functions to convert between valid XML and Text. (I tend to strip out the carriage returns as I don't usually need them.

CREATE FUNCTION dbo.udf_ConvertTextToXML (@Text varchar(MAX)) 
    RETURNS varchar(MAX)
AS
    BEGIN
        SET @Text = REPLACE(@Text,CHAR(10),'')
        SET @Text = REPLACE(@Text,CHAR(13),'')
        SET @Text = REPLACE(@Text,'<','&lt;')
        SET @Text = REPLACE(@Text,'&','&amp;')
        SET @Text = REPLACE(@Text,'>','&gt;')
        SET @Text = REPLACE(@Text,'''','&apos;')
        SET @Text = REPLACE(@Text,'"','&quot;')
    RETURN @Text
END


CREATE FUNCTION dbo.udf_ConvertTextFromXML (@Text VARCHAR(MAX)) 
    RETURNS VARCHAR(max)
AS
    BEGIN
        SET @Text = REPLACE(@Text,'&lt;','<')
        SET @Text = REPLACE(@Text,'&amp;','&')
        SET @Text = REPLACE(@Text,'&gt;','>')
        SET @Text = REPLACE(@Text,'&apos;','''')
        SET @Text = REPLACE(@Text,'&quot;','"')
    RETURN @Text
END

Answer 6

Check this

 SELECT A.OtherID,  
     Split.a.value('.', 'VARCHAR(100)') AS Data  
 FROM  
 (
     SELECT OtherID,  
         CAST ('<M>' + REPLACE(Data, ',', '</M><M>') + '</M>' AS XML) AS Data  
     FROM  Table1
 ) AS A CROSS APPLY Data.nodes ('/M') AS Split(a);