Placing a 1:N relation into one column is considered bad database design, and SQL Server doesn't even try to support it.
Despite all that, it's fairly common. You can search around the web for one of the many fnSplit
implementations. Here's one example:
CREATE FUNCTION dbo.fnSplit(
@sInputList VARCHAR(8000) -- List of delimited items
, @sDelimiter VARCHAR(8000) = ',' -- delimiter that separates items
) RETURNS @List TABLE (item VARCHAR(8000))
BEGIN
DECLARE @sItem VARCHAR(8000)
WHILE CHARINDEX(@sDelimiter,@sInputList,0) <> 0
BEGIN
SELECT
@sItem=RTRIM(LTRIM(SUBSTRING(@sInputList,1,CHARINDEX(@sDelimiter,@sInputList,0)-1))),
@sInputList=RTRIM(LTRIM(SUBSTRING(@sInputList,CHARINDEX(@sDelimiter,@sInputList,0)+LEN(@sDelimiter),LEN(@sInputList))))
IF LEN(@sItem) > 0
INSERT INTO @List SELECT @sItem
END
IF LEN(@sInputList) > 0
INSERT INTO @List SELECT @sInputList -- Put the last item in
RETURN
END
GO
--Test
select * from fnSplit('1,22,333,444,,5555,666', ',')
select * from fnSplit('1##22#333##444','##') --note second item has embedded #
select * from fnSplit('1 22 333 444 5555 666', ' ')