All errors › ORA errors
ORA-02291: Integrity constraint violated - parent key not found
What it means
An INSERT/UPDATE on a child table refers to a parent key value that does not exist.
How to fix it
Insert the parent row first (or in the same transaction with a deferrable constraint), and check the value for typos or wrong type conversions. The message names the foreign key constraint.
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.