FetchRequest

The type that tells how fetched database rows should be interpreted.

Returns a tuple that contains a prepared statement that is ready to be executed, and an eventual row adapter.

Returns the number of rows fetched by the request.

The default implementation builds a naive SQL query based on the statement returned by the prepare method: SELECT COUNT(*) FROM (...).

Adopting types can refine this method in order to use more efficient SQL.

A cursor over fetched values.

let request: ... // Some TypedRequest that fetches 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 dispath queue.

An array of fetched values.

let request: ... // Some TypedRequest that fetches String
let strings = try request.fetchAll(db) // [String]

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 TypedRequest that fetches String
let string = try request.fetchOne(db) // String?

A cursor over fetched optional values.

let request: ... // Some TypedRequest that fetches Optional<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 dispath queue.

An array of fetched optional values.

let request: ... // Some TypedRequest that fetches Optional<String>
let strings = try request.fetchAll(db) // [String?]

Returns an adapted request.

Returns the database region that the request looks into.

This default implementation returns a region built from the statement returned by the prepare method.

A cursor over fetched rows.

let request: ... // Some TypedRequest that fetches Row
let rows = try request.fetchCursor(db) // RowCursor
while let row = try rows.next() {  // Row
    let id: Int64 = row[0]
    let name: String = row[1]
}

Fetched rows are reused during the cursor iteration: don’t turn a row cursor into an array with Array(rows) or rows.filter { ... } since you would not get the distinct rows you expect. Use Row.fetchAll(...) instead.

For the same reason, make sure you make a copy whenever you extract a row for later use: row.copy().

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

The cursor must be iterated in a protected dispath queue.

An array of fetched rows.

let request: ... // Some TypedRequest that fetches Row
let rows = try request.fetchAll(db)

The first fetched row.

let request: ... // Some TypedRequest that fetches Row
let row = try request.fetchOne(db)

A cursor over fetched values.

let request: ... // Some TypedRequest that fetches 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 dispath queue.

An array of fetched values.

let request: ... // Some TypedRequest that fetches String
let strings = try request.fetchAll(db) // [String]

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 TypedRequest that fetches String
let string = try request.fetchOne(db) // String?

A cursor over fetched optional values.

let request: ... // Some TypedRequest that fetches Optional<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 dispath queue.

An array of fetched optional values.

let request: ... // Some TypedRequest that fetches Optional<String>
let strings = try request.fetchAll(db) // [String?]

A cursor over fetched records.

let request: ... // Some TypedRequest that fetches Player
let players = try request.fetchCursor(db) // Cursor of Player
while let player = try players.next() {   // Player
    ...
}

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

The cursor must be iterated in a protected dispath queue.

An array of fetched records.

let request: ... // Some TypedRequest that fetches Player
let players = try request.fetchAll(db) // [Player]

The first fetched record.

let request: ... // Some TypedRequest that fetches Player
let player = try request.fetchOne(db) // Player?