PostgresDB 42830: Invalid Foreign Key

Foreign key constraint is invalid.
  1. Identify the table and column causing the error by checking the error message details. Suppose the error indicates a problem with a foreign key between table_a and table_b.
  2. Verify the existence of the referenced row in the parent table:
  3. SELECT * FROM table_b WHERE id = <value_from_error_message>;
  4. If the above query returns no rows, it indicates the foreign key reference is invalid because the referenced data does not exist. Check if the data was deleted or if there was a typo in the inserted/updated data.
  5. Check for any recent changes in the database schema or data that might have caused this issue:
  6. SELECT * FROM pg_stat_activity WHERE query LIKE '%ALTER TABLE%';
  7. Ensure that any insert or update operation includes valid foreign key references. For inserts or updates, ensure the foreign key value exists in the referenced table before proceeding.
  8. If necessary, insert or update the missing data in the parent table (table_b) so that the foreign key constraint is satisfied:
  9. INSERT INTO table_b (id, ...) VALUES (<expected_value>, ...);
  10. Re-attempt the failed operation after ensuring the foreign key value exists in the parent table.

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