How to fix the Oracle error QSM-02004: grouping column omitted from SELECT list?

In this post, you’ll learn more about the Oracle ErrorQSM-02004: grouping column omitted from SELECT list with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

QSM-02004: grouping column omitted from SELECT list

Reason for the Error QSM-02004: grouping column omitted from SELECT list

The capability in question is not supported when the materialized view contains a column or expression in the GROUP BY clause that is not also present in the list of output select expressions.

How to fix the Error QSM-02004: grouping column omitted from SELECT list ?

You can fix this error in Oracle by following the below steps

Include all GROUP BY expressions in the output select list.