.NET Framework 4.5.2+
.NET Framework 4.5.2+
.NET Standard 2.0+
.NET Core 3.0+

RuleValueComparisonAttribute.TargetCollectionAggregate Property

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

Namespace: DevExpress.Persistent.Validation

Assembly: DevExpress.Persistent.Base.v21.1.dll

Declaration

public Aggregate TargetCollectionAggregate { get; set; }

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.

See Also