QueryBuilder.SumByNullable<'T,'Q,^Value> Method (F#)
A query operator that selects a nullable value for each element selected so far and returns the sum of these values. If any nullable element does not have a value, it is ignored.
Namespace/Module Path: Microsoft.FSharp.Linq
Assembly: FSharp.Core (in FSharp.Core.dll)
// Signature: member this.SumByNullable : QuerySource<'T,'Q> * ('T -> Nullable<^Value>) -> Nullable<^Value> when ^Value with static member (+) and ^Value with static member Zero and ^Value : (new : unit -> ^Value) and ^Value : struct and ^Value :> ValueType // Usage: queryBuilder.SumByNullable (source, valueSelector)