Error codes

import { isAlreadyExists, ALREADY_EXISTS_CODES } from "drizzle-migrate-neon-http/errors";

isAlreadyExists(code)

Returns true when a PostgreSQL error code is one of the known "object already exists" conditions that are safe to skip during migration.

Used internally by the runner's executeStatement so that re-running against a partially-applied schema heals rather than explodes.

isAlreadyExists("42P07"); // true
isAlreadyExists("23505"); // false — unique violation is NOT skipped

ALREADY_EXISTS_CODES

The exact set:

Code	Meaning
42P07	relation already exists
42701	column already exists
42710	object already exists
42P16	cannot change number of columns
42723	function already exists
42P17	index already exists

Design note

These codes represent desired end states — re-creating an object that's already there. They're intentionally narrow: transient errors, constraint violations (23505) and everything else are re-thrown so real problems surface loudly instead of being silently swallowed.