SQLSTATE 40002 signals that a transaction broke a deferred integrity constraint and has been rolled back.
transaction_integrity_constraint_violation (SQLSTATE 40002) occurs when a PostgreSQL transaction violates a deferred foreign-key, unique, or trigger-enforced rule at COMMIT. PostgreSQL aborts the entire transaction. Fix it by correcting the offending DML, validating constraints with SET CONSTRAINTS ALL IMMEDIATE, then re-running the transaction.
transaction_integrity_constraint_violation
PostgreSQL returns SQLSTATE 40002 when an open transaction violates an integrity rule that was deferred until commit time or raised by a trigger. The server marks the transaction as aborted and rejects further commands until a rollback.
The error protects database consistency.
All modifications since BEGIN are rolled back, so understanding and fixing the root cause is essential before retrying.
Deferred foreign-key or unique constraints can pass during individual statements but fail when evaluated at COMMIT.
AFTER-ROW triggers may issue RAISE EXCEPTION if business rules are broken, surfacing as 40002.
SET CONSTRAINTS ALL DEFERRED defers checks; later operations or concurrent sessions can invalidate earlier assumptions.
Bulk loads that write child rows first or change primary keys without cascading updates often produce this error.
Rollback the failed transaction to clear the session state.
Locate the first violating statement using application logs or SAVEPOINT checkpoints.
Correct the offending INSERT, UPDATE, or DELETE so that all referenced keys exist and unique values remain distinct.
Test the fix by running SET CONSTRAINTS ALL IMMEDIATE before COMMIT; if no error appears, the transaction can safely commit.
ETL jobs loading fact tables before dimensions fail at commit.
Load dimension (parent) rows first or make constraints NOT DEFERRABLE.
Soft-delete logic that updates primary keys instead of using ON UPDATE CASCADE causes duplicates. Avoid primary key changes or cascade them.
JSON-validating triggers raise exceptions on missing keys.
Provide defaults or relax trigger conditions.
Keep constraints NOT DEFERRABLE unless absolutely required; immediate checking surfaces issues earlier.
Use SAVEPOINTS around risky blocks so only part of the work rolls back on failure.
Load data in parent-first order during bulk imports or wrap loads in scripts that disable then re-enable constraints with VALIDATE CONSTRAINT.
Add integration tests that run SET CONSTRAINTS ALL IMMEDIATE before COMMIT to catch violations in CI.
23505 unique_violation - raised instantly on duplicate keys.
Ensure inserted values are unique.
23503 foreign_key_violation - triggered when a child references a missing parent. Load parents first or add ON DELETE/UPDATE CASCADE.
40001 serialization_failure - occurs during concurrent transactions. Employ retry logic or lower isolation level.
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Because the constraint is DEFERRABLE, PostgreSQL postpones validation until the end of the transaction, surfacing the violation at COMMIT.
No. PostgreSQL marks the entire transaction as failed, so all statements are rolled back.
No. Violating integrity constraints always aborts the transaction to protect data consistency.
Galaxy's AI Copilot scans your script, warns about missing parent keys, and lets you run SET CONSTRAINTS ALL IMMEDIATE mid-transaction to catch issues early.
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