axiom-database-migration

To safely add a new column to an SQLite database in your iOS app, use additive, idempotent migrations that preserve existing user data. This approach ensures schema changes apply safely to both fresh installs and existing users during upgrades.

The best way to handle SQLite schema changes with GRDB on macOS is to enforce transactional, immutable migrations. This protects user data during upgrades by ensuring complex refactors, type changes, and foreign key additions execute safely or roll back entirely.

Yes, you can change column types and backfill data in SwiftData without losing user records by applying safe, additive schema migrations. These migrations enforce NOT NULL constraints and ensure data preservation across existing user databases during upgrades.

Database migrations fail when adding NOT NULL columns to existing SQLite tables because existing rows lack valid values for the new constraint. Safe migration practices require backfilling data before applying NOT NULL constraints to preserve user records.

To test SQLite migrations for both fresh installs and existing iOS users, verify idempotent migration scripts against previous database versions. This process checks data preservation and confirms schema evolution applies correctly across all upgrade paths.