UnaryOperator Class

An unary operator which performs an operation on only one expression.

Namespace: DevExpress.Data.Filtering

Assembly: DevExpress.Data.v23.2.dll

NuGet Package: DevExpress.Data

Declaration

C#

public class UnaryOperator :
    CriteriaOperator

VB.NET

Public Class UnaryOperator
    Inherits CriteriaOperator

Related API Members

The following members return UnaryOperator objects:

• CriteriaOperator.IsNotNull()
• CriteriaOperator.IsNull()
• CriteriaOperator.Not()
• UnaryOperator.Clone()

Remarks

To create an unary operator, create a new instance of the UnaryOperator class with the specified settings. The UnaryOperator.OperatorType property specifies the type of the unary operator.

For more information on building criteria, see Simplified Criteria Syntax.

Tip

You can find examples in the following article: Build Criteria - Cheat Sheet.

Example

Example 1

Return orders that have Price is not between 20 and 30.

Expression:

LINQ

CriteriaOperator.FromLambda<Order>(o => !(o.Price >= 20 && o.Price <= 30));

Typed

new UnaryOperator(UnaryOperatorType.Not, new BetweenOperator(nameof(Order.Price), 20, 30));

String

CriteriaOperator.Parse("Not Price Between (20,30)");

Test

Input:

OrderName	Price
Order0	10
Order1	20
Order2	30
Order3	40

The result:

OrderName
Order0
Order3

Example 2

Return order items with the Order property references to null.

Expression:

LINQ

CriteriaOperator.FromLambda<OrderItem>(oi => oi.Order == null);

Typed

new UnaryOperator(UnaryOperatorType.IsNull, new OperandProperty(nameof(OrderItem.Order)));

String

CriteriaOperator.Parse("Order is null");

Test

Input:

OrderItemName	Order
OrderItem0	null
OrderItem1	Order1

The result:

OrderItemName
OrderItem0

Inheritance

Object

CriteriaOperator

UnaryOperator

NotOperator

NullOperator