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)
Parameters
source
Type: QuerySource<'T,'Q>The input query.
valueSelector
Type: 'T -> Nullable<^Value>A function to compute the values to sum.
Return Value
The resulting sum.
Remarks
For more information and examples, see Query Expressions (F#).
Platforms
Windows 8, Windows 7, Windows Server 2012, Windows Server 2008 R2
Version Information
F# Core Library Versions
Supported in: 4.0, Portable