FetchRequest

The protocol for all requests that fetch database rows, and tell how those rows should be interpreted.

struct Player: FetchableRecord { ... }
let request: some FetchRequest<Player> = ...

try request.fetchCursor(db) // Cursor of Player
try request.fetchAll(db)    // [Player]
try request.fetchSet(db)    // Set<Player>
try request.fetchOne(db)    // Player?
try request.fetchCount(db)  // Int

Fetching Values

  • fetchCursor(_:) Extension method

    A cursor over fetched values.

    let request: some FetchRequest<String> = ...
let strings = try request.fetchCursor(db) // Cursor of String
while let string = try strings.next() {   // String
    ...
}

    If the database is modified during the cursor iteration, the remaining elements are undefined.

    The cursor must be iterated in a protected dispatch queue.

    Throws

    A DatabaseError is thrown whenever an SQLite error occurs.
  • fetchAll(_:) Extension method

    An array of fetched values.

    let request: some FetchRequest<String> = ...
let strings = try request.fetchAll(db) // [String]

    Throws

    A DatabaseError is thrown whenever an SQLite error occurs.
  • fetchOne(_:) Extension method

    The first fetched value.

    The result is nil if the request returns no row, or if no value can be extracted from the first row.

    let request: some FetchRequest<String> = ...
let string = try request.fetchOne(db) // String?

    Throws

    A DatabaseError is thrown whenever an SQLite error occurs.

Cursors

  • fetchSet(_:) Extension method

    A set of fetched values.

    let request: some FetchRequest<String> = ...
let strings = try request.fetchSet(db) // Set<String>

    Throws

    A DatabaseError is thrown whenever an SQLite error occurs.

FetchRequest

  • databaseRegion(_:) Extension method

    Returns the database region that the request feeds from.

AdaptedFetchRequest

  • adapted(_:) Extension method

    Returns an adapted request.