// Use when writing raw SQL with GRDB, complex joins across 4+ tables, window functions, ValueObservation for reactive queries, or dropping down from SQLiteData for performance. Direct SQLite access for iOS/macOS with type-safe queries and migrations.
| name | grdb |
| description | Use when writing raw SQL with GRDB, complex joins across 4+ tables, window functions, ValueObservation for reactive queries, or dropping down from SQLiteData for performance. Direct SQLite access for iOS/macOS with type-safe queries and migrations. |
Direct SQLite access using GRDB.swift - type-safe Swift wrapper with full SQLite power when you need it.
ALWAYS load reference files if there is even a small chance the content may be required. It's better to have the context than to miss a pattern or make a mistake.
| Reference | Load When |
|---|---|
| Getting Started | Setting up DatabaseQueue or DatabasePool |
| Queries | Writing raw SQL, Record types, type-safe queries |
| Value Observation | Reactive queries, SwiftUI integration |
| Migrations | DatabaseMigrator, schema evolution |
| Performance | EXPLAIN QUERY PLAN, indexing, profiling |
| Scenario | Use |
|---|---|
| Type-safe @Table models | SQLiteData |
| CloudKit sync needed | SQLiteData |
| Complex joins (4+ tables) | GRDB |
| Window functions (ROW_NUMBER, RANK) | GRDB |
| Performance-critical raw SQL | GRDB |
| Reactive queries (ValueObservation) | GRDB |
Performance assumptions without EXPLAIN PLAN — Assuming your query is fast or slow without checking EXPLAIN QUERY PLAN is guessing. Always profile queries with EXPLAIN before optimizing.
Missing indexes on WHERE clauses — Queries filtering on non-indexed columns scan the entire table. Index any column used in WHERE, JOIN, or ORDER BY clauses for large tables.
Improper migration ordering — Running migrations out of order or skipping intermediate versions breaks schema consistency. Always apply migrations sequentially; never jump versions.
Record conformance shortcuts — Not conforming Record types to PersistableRecord or FetchableRecord correctly leads to silent data loss or deserialization failures. Always implement all required protocols correctly.
ValueObservation without proper cleanup — Forgetting to cancel ValueObservation when views disappear causes memory leaks and stale data subscriptions. Store the cancellable and clean up in deinit.
Use when building features with TCA (The Composable Architecture), structuring reducers, managing state, handling effects, navigation, or testing TCA features. Covers @Reducer, Store, Effect, TestStore, reducer composition, and TCA patterns.
Use when implementing iOS 26 features (Liquid Glass, new SwiftUI APIs, WebView, Chart3D), deploying iOS 26+ apps, or supporting backward compatibility with iOS 17/18.
Use when implementing iOS 17+ SwiftUI patterns: @Observable/@Bindable, MVVM architecture, NavigationStack, lazy loading, UIKit interop, accessibility (VoiceOver/Dynamic Type), async operations (.task/.refreshable), or migrating from ObservableObject/@StateObject.
Use when writing async/await code, enabling strict concurrency, fixing Sendable errors, migrating from completion handlers, managing shared state with actors, or using Task/TaskGroup for concurrency.
Use when implementing on-device AI with Apple's Foundation Models framework (iOS 26+), building summarization/extraction/classification features, or using @Generable for type-safe structured output.
Use when adding haptic feedback for user confirmations (button presses, toggles, purchases), error notifications, or custom tactile patterns (Core Haptics). Covers UIFeedbackGenerator and CHHapticEngine patterns.