Error 8163
Severity Level 16
Message Text
The text, ntext, or image data type cannot be selected as DISTINCT.
Explanation
When querying, Microsoft® SQL Server™ does not allow the use of SELECT DISTINCT on a text, ntext, or image column. For example, this query fails, returning error 8163:
USE Northwind
SELECT DISTINCT Description
FROM Categories
Action
Remove references to any text, ntext, or image columns when using SELECT DISTINCT.