AggregateOperand.Exists(CriteriaOperator) 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.v23.2.dll

NuGet Package: DevExpress.Data

Declaration

C#

public AggregateOperand Exists(
    CriteriaOperator aggregatedExpression
)

VB.NET

Public Function Exists(
    aggregatedExpression As CriteriaOperator
) As AggregateOperand

Parameters

Name	Type	Description
aggregatedExpression	CriteriaOperator	A CriteriaOperator object which specifies the aggregate expression.

Returns

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

Example

Check whether a collection has elements that match a criteria.

Expression:

LINQ

CriteriaOperator.FromLambda<Order>(o => o.OrderItems.Any(oi=>oi.ItemPrice==20)); ;

Typed

new AggregateOperand(nameof(Order.OrderItems), Aggregate.Exists,new BinaryOperator(nameof(OrderItem.ItemPrice),20));

String

CriteriaOperator.Parse("[OrderItems][ItemPrice=20]");

Test

Input:

Order	OrderItemName	ItemPrice
Order0
	OrderItem1	20
	OrderItem2	30

The result: True