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.

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

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

This method is not reentrant.

Synchronously executes a block in a protected dispatch queue, wrapped inside a transaction.

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

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

This method is not reentrant.

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(...)
}

This method is not reentrant.

Starting iOS 8.2, OSX 10.10, and with custom SQLite builds and SQLCipher, attempts to write in the database throw a DatabaseError whose resultCode is SQLITE_READONLY.

Alias for inDatabase. See DatabaseReader.unsafeRead.

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

try dbQueue.unsafeReentrantRead { db in
    try db.execute(...)
}

This method is reentrant. It should be avoided because it fosters dangerous concurrency practices.

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.inDatabase { db in
    try Int.fetchOne(db, "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.inDatabase { db in
    try db.execute("CREATE TABLE files (name TEXT COLLATE LOCALIZED_STANDARD")
}

Remove a collation.

Alias for inDatabase. See DatabaseWriter.write.

Synchronously executes block.

Starting iOS 8.2, OSX 10.10, and with custom SQLite builds and SQLCipher, attempts to write in the database throw a DatabaseError whose resultCode is SQLITE_READONLY.

This method must be called from the protected database dispatch queue, outside of a transaction. You’ll get a fatal error otherwise.

See DatabaseWriter.readFromCurrentState.

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

try dbQueue.unsafeReentrantWrite { db in
    try db.execute(...)
}

This method is reentrant. It should be avoided because it fosters dangerous concurrency practices.

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.