Msg 306, Level 16, State 2, Line 2
The text, ntext, and image data types cannot be compared or sorted, except when using IS NULL or LIKE operator.
This error message appears when you try to group by a column of the data type TEXT, NTEXT, or IMAGE.
The T-SQL statement can be parsed, but causes the error at runtime.
Error of the Severity Level 16 are generated by the user and can be fixed by the SQL Server user. You cannot use a BLOB column in a GROUP BY clause.
All versions of SQL Server.
IF OBJECT_ID(‘tempdb..#t’) > 0
DROP TABLE #t
CREATE TABLE #t
INSERT INTO #t SELECT ‘1’;
GROUP BY c1
In the above example we try to group by the c1 column. Because this is a column of a BLOB data type, the error is raised.