DatabaseQueue

The database configuration

The path to the database file; it is :memory: for in-memory databases.

Opens the SQLite database at path path.

let dbQueue = try DatabaseQueue(path: "/path/to/database.sqlite")

Database connections get closed when the database queue gets deallocated.

Opens an in-memory SQLite database.

let dbQueue = DatabaseQueue()

Database memory is released when the database queue gets deallocated.

Free as much memory as possible.

This method blocks the current thread until all database accesses are completed.

See also setupMemoryManagement(application:)

Listens to UIApplicationDidEnterBackgroundNotification and UIApplicationDidReceiveMemoryWarningNotification in order to release as much memory as possible.

• param application: The UIApplication that will start a background task to let the database queue release its memory when the application enters background.

Synchronously executes a read-only block in a protected dispatch queue, and returns its result.

let players = try dbQueue.read { db in
    try Player.fetchAll(db)
}

This method is not reentrant.

Starting SQLite 3.8.0 (iOS 8.2+, OSX 10.10+, custom SQLite builds and SQLCipher), attempts to write in the database from this method throw a DatabaseError of resultCode SQLITE_READONLY.

Asynchronously executes a read-only block in a protected dispatch queue.

let players = try dbQueue.asyncRead { result in
    do {
        let db = try result.get()
        let count = try Player.fetchCount(db)
    } catch {
        // Handle error
    }
}

Starting SQLite 3.8.0 (iOS 8.2+, OSX 10.10+, custom SQLite builds and SQLCipher), attempts to write in the database from this method throw a DatabaseError of resultCode SQLITE_READONLY.

Synchronously executes database updates in a protected dispatch queue, wrapped inside a transaction, and returns the result.

If the updates throws an error, the transaction is rollbacked and the error is rethrown. If the updates return .rollback, the transaction is also rollbacked, but no error is thrown.

Eventual concurrent database accesses are postponed until the transaction has completed.

This method is not reentrant.

try dbQueue.writeInTransaction { db in
    db.execute(...)
    return .commit
}

Synchronously executes database updates in a protected dispatch queue, outside of any transaction, and returns the result.

Eventual concurrent database accesses are postponed until the updates are completed.

This method is not reentrant.

Synchronously executes database updates in a protected dispatch queue, outside of any transaction, and returns the result.

// INSERT INTO player ...
let players = try dbQueue.inDatabase { db in
    try Player(...).insert(db)
}

This method is not reentrant.

Synchronously executes database updates in a protected dispatch queue, and returns the result.

// INSERT INTO player ...
try dbQueue.unsafeReentrantWrite { db in
    try Player(...).insert(db)
}

This method is reentrant. It is unsafe because it fosters dangerous concurrency practices.

Asynchronously executes database updates in a protected dispatch queue, outside of any transaction.

Add or redefine an SQL function.

let fn = DatabaseFunction("succ", argumentCount: 1) { dbValues in
    guard let int = Int.fromDatabaseValue(dbValues[0]) else {
        return nil
    }
    return int + 1
}
dbQueue.add(function: fn)
try dbQueue.read { db in
    try Int.fetchOne(db, sql: "SELECT succ(1)") // 2
}

Remove an SQL function.

Add or redefine a collation.

let collation = DatabaseCollation("localized_standard") { (string1, string2) in
    return (string1 as NSString).localizedStandardCompare(string2)
}
dbQueue.add(collation: collation)
try dbQueue.write { db in
    try db.execute(sql: "CREATE TABLE file (name TEXT COLLATE LOCALIZED_STANDARD")
}

Remove a collation.