AggregateOperand.Exists() Method

Creates a new AggregateOperand which determines whether or not the count of AggregateOperand.CollectionProperty elements that match the AggregateOperand.Condition is greater than zero.

Namespace: DevExpress.Data.Filtering

Assembly: DevExpress.Data.v23.1.dll

NuGet Package: DevExpress.Data

Declaration

C#

public AggregateOperand Exists()

VB.NET

Public Function Exists As AggregateOperand

Returns

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

Example

Check whether a collection has items.

Expression:

LINQ

CriteriaOperator.FromLambda<Order>(o => o.OrderItems.Any());

Typed

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

String

CriteriaOperator.Parse("OrderItems.Exists()");

Test

Input:

Order	OrderItemName
Order0
	OrderItem1
	OrderItem2

The result: True