[sql] Where value in column containing comma delimited values

I wish to write an SQL statement for SQL Server 2008 that Selects entry's where a column contains a value, now the value within the column is a comma delimited list (usually - there could only be one entry (and no leading comma)) so what In checking for is "is this value contained somewhere within the list?", for instance:

COLUMN = Cat, Dog, Sparrow, Trout, Cow, Seahorse
Does COLUMN contain Cat? YES
Does COLUMN contain horse? NO
Does COLUMN contain Sheep? NO

or

COLUMN = Mouse
Does COLUMN contain Hare? NO
Does COLUMN contain Mouse? YES

etc

I was thinking I could use the 'IN' keyword as such

SELECT id_column FROM table_name WHERE 'Cat' IN COLUMN

but this does not work as it seems that you can only use that to check if a column contains one of a series of comma delimited values.

I also cannot use CONTAINS() OR 'LIKE' as this, in the above example would return values for 'horse' as the whole string contains horse in 'Seahorse', and I can't search for the needle plus a comma (if I'm looking for 'horse' the search would be 'horse,') as what if the entry is at the end of a the list? And I can't search for a comma plus a needle (if I'm looking for 'horse' the search would be ',horse') as what if the entry is the first in the list? And I can't use both as what if the entry is the only (single) entry?

Although the tricky solution @tbaxter120 advised is good but I use this function and work like a charm, pString is a delimited string and pDelimiter is a delimiter character:

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

ALTER FUNCTION [dbo].[DelimitedSplit]
--===== Define I/O parameters
        (@pString NVARCHAR(MAX), @pDelimiter CHAR(1))
RETURNS TABLE WITH SCHEMABINDING AS
 RETURN
--===== "Inline" CTE Driven "Tally Table" produces values from 0 up to 10,000...
     -- enough to cover VARCHAR(8000)
  WITH E1(N) AS (
                 SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL 
                 SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL 
                 SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1
                ),                          --10E+1 or 10 rows
       E2(N) AS (SELECT 1 FROM E1 a, E1 b), --10E+2 or 100 rows
       E4(N) AS (SELECT 1 FROM E2 a, E2 b), --10E+4 or 10,000 rows max
 cteTally(N) AS (--==== This provides the "base" CTE and limits the number of rows right up front
                     -- for both a performance gain and prevention of accidental "overruns"
                 SELECT TOP (ISNULL(DATALENGTH(@pString),0)) ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) FROM E4
                ),
cteStart(N1) AS (--==== This returns N+1 (starting position of each "element" just once for each delimiter)
                 SELECT 1 UNION ALL -- does away with 0 base CTE, and the OR condition in one go!
                 SELECT t.N+1 FROM cteTally t WHERE SUBSTRING(@pString,t.N,1) = @pDelimiter
                ),
cteLen(N1,L1) AS(--==== Return start and length (for use in substring)
                 SELECT s.N1,
                        ---ISNULL(NULLIF(CHARINDEX(@pDelimiter,@pString,s.N1),0)-s.N1,8000)
                        ISNULL(NULLIF(CHARINDEX(@pDelimiter,@pString,s.N1),0)-s.N1,50000)
                   FROM cteStart s
                )
--===== Do the actual split. The ISNULL/NULLIF combo handles the length for the final element when no delimiter is found.
 SELECT ItemNumber = ROW_NUMBER() OVER(ORDER BY l.N1),
        Item       = SUBSTRING(@pString, l.N1, l.L1)
   FROM cteLen l

;

Then for example you can call it in where clause as below:

WHERE [fieldname] IN (SELECT LTRIM(RTRIM(Item)) FROM [dbo].[DelimitedSplit]('2,5,11', ','))

Hope this help.

WHERE
      MyColumn LIKE '%,' + @search + ',%' --middle
      OR
      MyColumn LIKE @search + ',%' --start
      OR
      MyColumn LIKE '%,' + @search --end
      OR 
      MyColumn =  @search --single (good point by Cheran S in comment)

If you know the ID's rather than the strings, use this approach:

where mylookuptablecolumn IN (myarrayorcommadelimitedarray)

Just make sure that myarrayorcommadelimitedarray is not put in string quotes.

works if you want A OR B, but not AND.

SELECT * FROM TABLENAME WHERE FIND_IN_SET(@search, column)

If it turns out your column has whitespaces in between the list items, use

SELECT * FROM TABLENAME WHERE FIND_IN_SET(@search, REPLACE(column, ' ', ''))

http://dev.mysql.com/doc/refman/5.0/en/string-functions.html

The solution tbaxter120 suggested worked for me but I needed something that will be supported both in MySQL & Oracle & MSSQL, and here it is:

WHERE (CONCAT(',' ,CONCAT(RTRIM(MyColumn), ','))) LIKE CONCAT('%,' , CONCAT(@search , ',%'))

The best solution in this case is to normalize your table to have the comma separated values in different rows (First normal form 1NF) http://en.wikipedia.org/wiki/First_normal_form

For that, you can implement a nice Split table valued function in SQL, by using CLR http://bi-tch.blogspot.com/2007/10/sql-clr-net-function-split.html or using plain SQL.

CREATE FUNCTION dbo.Split
(
    @RowData nvarchar(2000),
    @SplitOn nvarchar(5)
)  
RETURNS @RtnValue table 
(
    Id int identity(1,1),
    Data nvarchar(100)
) 
AS  
BEGIN 
    Declare @Cnt int
    Set @Cnt = 1

    While (Charindex(@SplitOn,@RowData)>0)
    Begin
        Insert Into @RtnValue (data)
        Select 
            Data = ltrim(rtrim(Substring(@RowData,1,Charindex(@SplitOn,@RowData)-1)))

        Set @RowData = Substring(@RowData,Charindex(@SplitOn,@RowData)+1,len(@RowData))
        Set @Cnt = @Cnt + 1
    End

    Insert Into @RtnValue (data)
    Select Data = ltrim(rtrim(@RowData))

    Return
END

Then you can query the normalized output by using cross apply

select distinct a.id_column
from   MyTable a cross apply
       dbo.Split(A.MyCol,',') b
where  b.Data='Cat'

I found this answer on another forum, works perfect. No problems with finding 1 if there is also a 10

WHERE tablename REGEXP "(^|,)@search(,|$)"

I found it here

SELECT * FROM TABLE_NAME WHERE
        (
            LOCATE(',DOG,', CONCAT(',',COLUMN,','))>0 OR
            LOCATE(',CAT,', CONCAT(',',COLUMN,','))>0
        );

Since you don't know how many comma-delimited entries you can find, you may need to create a function with 'charindex' and 'substring' SQL Server functions. Values, as returned by the function could be used in a 'in' expression.

You function can be recursively invoked or you can create loop, searching for entries until no more entries are present in the string. Every call to the function uses the previous found index as the starting point of the next call. The first call starts at 0.

Just came to know about this when I was searching for a solution to a similar problem. SQL has a new keyword called CONTAINS you can use that. For more details see http://msdn.microsoft.com/en-us/library/ms187787.aspx

Where value in column containing comma delimited values search with multiple comma delimited

            declare @d varchar(1000)='-11,-12,10,121'

            set @d=replace(@d,',',',%'' or '',''+a+'','' like ''%,')

            print @d
            declare @d1 varchar(5000)=
            'select * from (
            select ''1,21,13,12'' as a
            union
            select ''11,211,131,121''
            union
            select ''411,211,131,1211'') as t
             where '',''+a+'','' like ''%,'+@d+ ',%'''

             print @d1
             exec (@d1)

DECLARE @search VARCHAR(10);
SET @search = 'Cat';

WITH T(C)
AS
(
SELECT 'Cat, Dog, Sparrow, Trout, Cow, Seahorse'
)
SELECT *
FROM T 
WHERE ', ' + C + ',' LIKE '%, ' + @search + ',%'

This will of course require a full table scan for every search.

select *
from YourTable
where ','+replace(col, ' ', '')+',' like '%,Cat,%'