JoinOperand Class

An operator that joins persistent objects on a specified condition, and calculates aggregate functions against matching objects.

Namespace: DevExpress.Data.Filtering

Assembly: DevExpress.Data.v20.1.dll

Declaration

public class JoinOperand :
    CriteriaOperator,
    IAggregateOperand,
    ICustomAggregateOperand
Public Class JoinOperand
    Inherits CriteriaOperator
    Implements IAggregateOperand,
               ICustomAggregateOperand

Remarks

Use the JoinOperand to build criteria and calculate aggregate functions using the properties of persistent objects that don't have explicitly defined associations. Persistent objects, to which the current JoinOperand is applied, are called parent objects for the join. To specify the type of persistent objects to be joined with parent objects, use the JoinOperand.JoinTypeName property.

The JoinOperand does the following:

Refer to the Free Joins help topic, to learn how to use the JoinOperand.

NOTE
  • For performance reasons, we recommend that you not use the JoinOperand when filtering or sorting the XPCollection on the client side, as this significantly increases the number of queries sent to the server.
  • JoinOperand may produce null instead of zero for an empty collection on a server side.

Inheritance

See Also