ORA-01791: not a SELECTed expression
Solution 1:
The problem here is the ORDER BY
column TITLE
isn't selected in the DISTINCT
query. Since DISTINCT
is used, the SELECT
query will try to group the resultset
based on the selected columns.
ORDER BY
column isn't selected here, it doesn't ensure the uniqueness on the resultset
and hence it fails to apply ORDER BY
.