DatabaseSnapshot

public class DatabaseSnapshot : DatabaseReader

A DatabaseSnapshot sees an unchanging database content, as it existed at the moment it was created.

See DatabasePool.makeSnapshot()

For more information, read about snapshot isolation at https://sqlite.org/isolation.html

Reading from Database

  • Synchronously executes a read-only block that takes a database connection, and returns its result.

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

    Throws

    The error thrown by the block.

    Declaration

    Swift

    public func read<T>(_ block: (Database) throws -> T) rethrows -> T

    Parameters

    block

    A block that accesses the database.
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  • Asynchronously executes a read-only block in a protected dispatch queue.

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

    Declaration

    Swift

    public func asyncRead(_ block: @escaping (Result<Database, Error>) -> Void)

    Parameters

    block

    A block that accesses the database.
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Functions

Collations

Value Observation