PostgreSQL Error Troubleshooting

When PostgreSQL rejects a statement, capture the complete error message and five-character SQLSTATE. SQLSTATE codes are stable across releases and do not depend on the server’s message language. See the PostgreSQL 18 error code appendix.

Query syntax errors

• Error 42601: syntax error

Object and schema errors

• Error 42702: column reference is ambiguous
• Error 42703: column does not exist
• Error 42P01: relation does not exist

Connection and authentication errors

• Error 28P01: password authentication failed

Access control errors

• Error 42501: permission denied

Constraint errors

• Error 23502: NOT NULL violation
• Error 23503: foreign key violation
• Error 23505: duplicate key violates a unique constraint
• Error 23514: CHECK constraint violation