All errors › ORA errors
ORA-01790: Expression must have same datatype as corresponding expression
What it means
Columns of UNION/INTERSECT/MINUS branches have different types at the same position.
How to fix it
Convert explicitly (TO_CHAR, CAST) so each position has the same type; use CAST(NULL AS type) for empty columns.
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.