AggregateOperand.Count() Method

Creates a new AggregateOperand which returns the count of AggregateOperand.CollectionProperty elements that match the AggregateOperand.Condition.

Namespace: DevExpress.Data.Filtering

Assembly: DevExpress.Data.v23.1.dll

NuGet Package: DevExpress.Data

Declaration

C#

public AggregateOperand Count()

VB.NET

Public Function Count As AggregateOperand

Returns

Type	Description
AggregateOperand	An AggregateOperand object which calculates an aggregate expression.

Example

Example 1

Get amount of all orders.

Expression:

LINQ

CriteriaOperator.FromLambda<Order, double>(x => FromLambdaFunctions.TopLevelAggregate<Order>().Count());

Typed

new AggregateOperand(null, Aggregate.Count);

String

CriteriaOperator.Parse("Count()");

Test

Input:

Order
Order0
Order1

The result: 2

Example 2

Get orders with more than 1 order items.

Expression:

LINQ

CriteriaOperator.FromLambda<Order>(x => x.OrderItems.Count() > 1);

Typed

new AggregateOperand(nameof(Order.OrderItems), Aggregate.Count);

String

CriteriaOperator.Parse("OrderItems.Count()>1");

Test

Input:

Order	OrderItem
Order0
	Item0-0
	Item0-1
Order1
	Item1-0
Order2
	Item2-0
	Item2-1

The result:

Order
Order0
Order2