# Queryable.Sum Method (IQueryable<Nullable<Decimal>>)

.NET Framework (current version)

Computes the sum of a sequence of nullable Decimal values.

Namespace:   System.Linq
Assembly:  System.Core (in System.Core.dll)

## Syntax

```public static Nullable<decimal> Sum(
this IQueryable<Nullable<decimal>> source
)
```

#### Parameters

source
Type:

A sequence of nullable Decimal values to calculate the sum of.

#### Return Value

Type:

The sum of the values in the sequence.

## Exceptions

Exception Condition
ArgumentNullException

source is null.

OverflowException

The sum is larger than MaxValue.

## Remarks

The Sum(IQueryable<Nullable<Decimal>>) method generates a MethodCallExpression that represents calling Sum(IQueryable<Nullable<Decimal>>) itself as a constructed generic method. It then passes the MethodCallExpression to the Execute<TResult>(Expression) method of the IQueryProvider represented by the Provider property of the source parameter.

The query behavior that occurs as a result of executing an expression tree that represents calling Sum(IQueryable<Nullable<Decimal>>) depends on the implementation of the type of the source parameter. The expected behavior is that it returns the sum of the values in source.

## Examples

The following code example demonstrates how to use Sum(IQueryable<Nullable<Single>>) to sum the values of a sequence.

Note

This code example uses an overload of this overloaded method that is different from the specific overload that this topic describes. To extend the example to this topic, substitute the elements of the source sequence with elements of the appropriate numerical type.

```float?[] points = { null, 0, 92.83F, null, 100.0F, 37.46F, 81.1F };

float? sum = points.AsQueryable().Sum();

Console.WriteLine("Total points earned: {0}", sum);

/*
This code produces the following output:

Total points earned: 311.39
*/

```

## Version Information

Universal Windows Platform
Available since 8
.NET Framework
Available since 3.5
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.1
Windows Phone
Available since 8.1