Cannot put expression on select list.

There are limitations to what expressions are allowed in the select list. The expression you are trying to add may be invalid. Verify that the syntax in the expression is correct. It is possible that the type of expression is invalid. For more information, see Expressions (Database Engine) and Expressions (Transact-SQL).

See Also

Concepts

Error Messages in Visual Database Tools

Help and Information

Getting SQL Server 2005 Assistance