SharingGRDB

A lightweight replacement for SwiftData and @Query.

• Learn more
• Overview
• Demos
• Documentation
• Installation
• Community
• License

Learn more

This library was motivated and designed over the course of many episodes on
Point-Free, a video series exploring advanced programming topics in the
Swift language, hosted by Brandon Williams and
Stephen Celis. To support the continued development of this
library, subscribe today.

Overview

SharingGRDB is lightweight replacement for SwiftData and the @Query macro that deploys all the way
back to the iOS 13 generation of targets.

@SharedReader(
  .fetchAll(
    sql: "SELECT * FROM items"
  )
)
var items: [Item]

@Query
var items: [Item]

Both of the above examples fetch items from an external data store, and both are automatically
observed by SwiftUI so that views are recomputed when the external data changes, but SharingGRDB is
powered directly by SQLite using Sharing and GRDB, and is
usable from UIKit, @Observable models, and more.

Note: It is not required to write queries as a raw SQL string, and a query builder can be used
instead. For more information on SharingGRDB’s querying capabilities, see
Fetching model data.

Quick start

Before SharingGRDB’s property wrappers can fetch data from SQLite, you need to provide–at
runtime–the default database it should use. This is typically done as early as possible in your
app’s lifetime, like the app entry point in SwiftUI, and is analogous to configuring model storage
in SwiftData:

@main
struct MyApp: App {
  init() {
    prepareDependencies {
      let db = try! DatabaseQueue(
        // Create/migrate a database 
        // connection
      )
      $0.defaultDatabase = db
    }
  }
  // ...
}

@main
struct MyApp: App {
  let container = { 
    // Create/configure a container
    try! ModelContainer(/* ... */)
  }()
  
  var body: some Scene {
    WindowGroup {
      ContentView()
        .modelContainer(container)
    }
  }
}

Note: For more information on preparing a SQLite database, see
Preparing a SQLite database.

This defaultDatabase connection is used implicitly by SharingGRDB’s strategies, like
fetchAll:

@SharedReader(.fetchAll(sql: "SELECT * FROM items"))
var items: [Item]

And you can access this database throughout your application in a way similar to how one accesses
a model context, via a property wrapper:

@Dependency(\.defaultDatabase) 
var database
    
var newItem = Item(/* ... */)
try database.write { db in
  try newItem.insert(db)
}

@Environment(\.modelContext) 
var modelContext
    
let newItem = Item(/* ... */)
modelContext.insert(newItem)
try modelContext.save()

Note: For more information on how SharingGRDB compares to SwiftData, see
Comparison with SwiftData.

This is all you need to know to get started with SharingGRDB, but there’s much more to learn. Read
the articles below to learn how to best utilize this library:

• Fetching model data
• Observing changes to model data
• Preparing a SQLite database
• Dynamic queries
• Comparison with SwiftData

SQLite knowledge required

SQLite is one of the
most established and widely distributed pieces of
software in the history of software. Knowledge of SQLite is a great skill for any app developer to
have, and this library does not want to conceal it from you. So, we feel that to best wield this
library you should be familiar with the basics of SQLite, including schema design and normalization,
SQL queries, including joins and aggregates, and performance, including indices.

With some basic knowledge you can apply this library to your database schema in order to query
for data and keep your views up-to-date when data in the database changes. You can use GRDB’s
query builder APIs to query your database, or you can use raw SQL queries,
along with all of the power that SQL has to offer.

Demos

This repo comes with lots of examples to demonstrate how to solve common and complex problems with
Sharing. Check out this directory to see them all, including:

• Case Studies:
  A number of case studies demonstrating the built-in features of the library.

• SyncUps: We also rebuilt Apple’s Scrumdinger demo
  application using modern, best practices for SwiftUI development, including using this library
  to query and persist state using SQLite.

• Reminders: A rebuild of Apple’s Reminders app
  that uses a SQLite database to model the reminders, lists and tags. It features many advanced
  queries, such as searching, and stats aggregation.

Documentation

The documentation for releases and main are available here:

• main
• 0.1.0

Installation

You can add SharingGRDB to an Xcode project by adding it to your project as a package.

https://github.com/pointfreeco/sharing-grdb

If you want to use SharingGRDB in a SwiftPM project, it’s as
simple as adding it to your Package.swift:

dependencies: [
  .package(url: "https://github.com/pointfreeco/sharing-grdb", from: "0.1.0")
]

And then adding the product to any target that needs access to the library:

.product(name: "SharingGRDB", package: "sharing-grdb"),

Community

If you want to discuss this library or have a question about how to use it to solve a particular
problem, there are a number of places you can discuss with fellow
Point-Free enthusiasts:

• For long-form discussions, we recommend the
  discussions tab of this repo.

• For casual chat, we recommend the
  Point-Free Community Slack.

License

This library is released under the MIT license. See LICENSE for details.