How can I check whether a number is contained in comma separated list stored in a varchar column?

Question

I have a table with a varchar column categoryIds. It contains some IDs separated by commas, for example:

id       categoryIds
-----         


        

Answer 1

Not sure if this would be faster or slower than DavidG's suggestion, but in order to get the same matches with only one check, you can do:

DECLARE @categoryId INT
SET @categoryId = 3

SELECT *
FROM myTable
WHERE CHARINDEX(',' + CAST(@categoryId AS VARCHAR(MAX)) + ',', ',' + categoryIds + ',') > 0