All errors › ORA errors
ORA-01861: Literal does not match format string
What it means
The input string does not have the shape of the format mask (different separators, missing parts), often because no mask was given and the session NLS_DATE_FORMAT differs from the data.
How to fix it
Pass a mask that matches the data exactly, or use DATE/TIMESTAMP literals. Never rely on implicit date conversion.
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.