Instance Method
sum(_:)
func sum<Field>(_ key: KeyPath<Model, Field>) -> EventLoopFuture<Field.Value> where Field : QueryableProperty, Model.IDValue == Field.Model, Field.Value : OptionalType
Instance Method
func sum<Field>(_ key: KeyPath<Model, Field>) -> EventLoopFuture<Field.Value> where Field : QueryableProperty, Model.IDValue == Field.Model, Field.Value : OptionalType