Dynamic SQL (watch for SQL injection) or a string splitter function. I recommend the latter. Search this site for 'Delimited8kSplit'
Oh, and as for why your attempt failed, that equates to this:
WHERE [AttributeID] = '1 OR [AttributeID] = 3 OR [AttributeID] = 6 OR [AttributeID] = 2808';
ie where the attribute is equal to that long string, which I'm sure you'll agree isn't going to do what you want
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)SQL In The Wild
: Discussions on DB performance with occasional diversions into recoverability
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