generatedAs(sql:_:)

Defines the column as a generated column.

iOS: 15+
macOS: 12+
tvOS: 15+
watchOS: 8+

@discardableResult func generatedAs(sql: String, _ qualification: GeneratedColumnQualification = .virtual) -> Self

Mangled symbol

s4GRDB16ColumnDefinitionC11generatedAs3sql_ACXDSS_AC09GeneratedB13QualificationOtF What are these?

FNV24 hash: 5YXS1

Parameters

sql: An SQL expression.
qualification: The generated column’s qualification, which defaults to virtual.

Returns

self so that you can further refine the column definition.

For example:

// CREATE TABLE player(
//   id INTEGER PRIMARY KEY AUTOINCREMENT,
//   score INTEGER NOT NULL,
//   bonus INTEGER NOT NULL,
//   totalScore INTEGER GENERATED ALWAYS AS (score + bonus) VIRTUAL
// )
try db.create(table: "player") { t in
    t.autoIncrementedPrimaryKey("id")
    t.column("score", .integer).notNull()
    t.column("bonus", .integer).notNull()
    t.column("totalScore", .integer).generatedAs(sql: "score + bonus")
}

To remove the generated columns from the selection of record types, define their databaseSelection:

struct Player: Codable {
    // No property for `totalScore`
    var id: Int64
    var score: Int
    var bonus: Int
}

extension Player: FetchableRecord, PersistableRecord {
    static var databaseSelection: [any SQLSelectable] {
        // Option 1
        [Column("id"), Column("score"), Column("bonus")]
        // Option 2
        [.allColumns(excluding: ["totalScore"])]
    }
}

// SELECT id, score, bonus FROM player
let players = try dbQueue.read { db in
    try Player.fetchAll(db)
}

Related SQLite documentation: https://sqlite.org/gencol.html