All errors › ORA errors
ORA-00979: Not a GROUP BY expression
What it means
An expression in the SELECT list, HAVING or ORDER BY is neither aggregated nor exactly listed in GROUP BY.
How to fix it
Add the expression to GROUP BY exactly as written in SELECT (column aliases are not allowed in GROUP BY before Oracle 23ai), or aggregate it (MAX(col)).
Catch it before it runs
ORA Error Helper
Explains ORA-/PLS- codes inside JetBrains IDEs and DataGrip. PL/SQL Lint
Flags risky PL/SQL patterns while you type. Oracle Plan Reader
Reads execution plans and points at the slow step. PL/SQL in Practice
Kindle book with practical PL/SQL for working developers.
Explains ORA-/PLS- codes inside JetBrains IDEs and DataGrip. PL/SQL Lint
Flags risky PL/SQL patterns while you type. Oracle Plan Reader
Reads execution plans and points at the slow step. PL/SQL in Practice
Kindle book with practical PL/SQL for working developers.
Nearby errors
Updated 2026-11-12.