SQL 2005 Split Comma Separated Column on Delimiter

Question

My google searches on how to split a string on a delimiter have resulted in some useful functions for splitting strings when the string is known (i.e. see below):

Answer 1

Fix it the right way--make that column a related table. No good ever comes of comma-separated scalar columns.

Answer 2

You could try something like:

SELECT s.Items AS SplitValue, ValueColumn1, ValueColumn2 
FROM MyTable, Split(CommaColumn,',') AS s

Answer 3

+1 to the anti-CSV comments, but if you must do this you would use CROSS APPLY or OUTER APPLY.

Answer 4

Yes, it's possible with CROSS APPLY (SQL 2005+):

with testdata (CommaColumn, ValueColumn1, ValueColumn2) as (
  select 'ABC,123', 1, 2 union all
  select 'XYZ, 789', 2, 3
  ) 
select 
  b.items as SplitValue
, a.ValueColumn1
, a.ValueColumn2
from testdata a
cross apply dbo.Split(a.CommaColumn,',') b

Notes:

1. You should add an index to the result set of your split column, so that it returns two columns, IndexNumber and Value.

2. In-line implementations with a numbers table are generally faster than your procedural version here.

eg:

create function [dbo].[Split] (@list nvarchar(max), @delimiter nchar(1) = N',')
returns table
as
return (
  select 
    Number = row_number() over (order by Number)
  , [Value] = ltrim(rtrim(convert(nvarchar(4000),
        substring(@list, Number
        , charindex(@delimiter, @list+@delimiter, Number)-Number
        )
    )))
  from dbo.Numbers
  where Number <= convert(int, len(@list))
    and substring(@delimiter + @list, Number, 1) = @delimiter
  )

Erland Sommarskog has the definitive page on this, I think: http://www.sommarskog.se/arrays-in-sql-2005.html

Answer 5

alter procedure [dbo].[usp_split](@strings varchar(max)) as  
begin  
    Declare @index int  
    set @index=1  
    declare @length int  
    set @length=len(@strings)  
    declare @str varchar(max)  
    declare @diff int  
    declare @Tags table(id varchar(30))  
    while(@index<@length)  
    begin  
        if(@index='1')  
        begin  
            set @str=(SELECT substring(@strings, @index, (charindex(',',(substring(@strings, @index,(@length)))))-1))  
            insert into @Tags values(@str)  
                set @index=(charindex(',',(substring(@strings, @index,(@length)))))  
        end  
        else  
        begin  
            set @diff=@length-@index  
            if(@diff !=0)  
            begin  
                set @str=(select substring(@strings, @index, (charindex(',',(substring(@strings,@index,@diff))))-1))  
                if(@str is not null and @str!='')  
                begin  
                    insert into @Tags VALUES(@str)  
                end  
                set @index=@index +(charindex(',',(substring(@strings, @index,@diff))))  
            end  
        end
    end
    set @str=(select right(@strings,(charindex(',',(substring(reverse(@strings),1,(@length)))))-1)) 
    insert into @Tags VALUES(@str)   
    select id from @Tags  
end

Usage:

exec usp_split '1212,21213,1,3,133,1313131,1,231313,5'