RuleValueComparisonAttribute.TargetCollectionAggregate Property

Specifies the aggregate function to be checked by the current rule.

Namespace: DevExpress.Persistent.Validation

Assembly: DevExpress.Persistent.Base.v23.2.dll

NuGet Package: DevExpress.Persistent.Base

Declaration

C#

public Aggregate TargetCollectionAggregate { get; set; }

VB.NET

Public Property TargetCollectionAggregate As Aggregate

Property Value

Type	Description
Aggregate	A Devexpress.Data.Filtering.Aggregate enumeration value which specifies the aggregate function to be checked by the current rule.

Available values:

Name	Description
Exists	Determines whether the object exists in the collection.
Count	Returns the number of objects in the collection.
Max	Returns the maximum expression value in the collection.
Min	Returns the minimum expression value in the collection.
Avg	Evaluates the average of the values in the collection.
Sum	Returns the sum of all the expression values in the collection.
Single	Returns a single object from the collection. The collection must contain no more than one object.
Custom	Returns a custom aggregate function‘s result.

Remarks

When applied to collection properties, the RuleValueComparison can use aggregate functions. When a value is assigned to the TargetCollectionAggregate property, the validation rule checks the specified aggregate function.

RuleValueComparison is not checked if the collection property is empty. Use the RuleRequiredFieldAttribute instead.