Aggregate Enum

Enumerates aggregate functions.

Namespace: DevExpress.Data.Filtering

Assembly: DevExpress.Data.v18.1.dll

Declaration

C#

public enum Aggregate

VB.NET

Public Enum Aggregate

Members

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.

Related API Members

The following properties accept/return Aggregate values:

Library	Related API Members
Cross-Platform Class Library	AggregateOperand.AggregateType
	JoinOperand.AggregateType
eXpressApp Framework	IRuleSupportsCollectionAggregatesProperties.TargetCollectionAggregate
	RuleRangeAttribute.TargetCollectionAggregate
	RuleRangeProperties.TargetCollectionAggregate
	RuleValueComparisonAttribute.TargetCollectionAggregate
	RuleValueComparisonProperties.TargetCollectionAggregate

Remarks

The values listed in this enumeration are used to set the AggregateOperand.AggregateType property.

Note

• AggregateOperand does not support nested expressions and complex property paths like “Max(Document.<PersonID>LastName)”. Only names of owned properties are supported: “Max(Document)”.

• AggregateOperand may produce null instead of zero for an empty collection on a server side.

Related GitHub Examples

The following code snippets (auto-collected from DevExpress Examples) contain references to the Aggregate enum.

Note

The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.

C#

how-to-bind-an-aspnet-mvc-gridview-extension-to-a-table-with-an-unknown-schema-using-custo-t602001/CS/XPCustomBindingExample/XPO/XpoBindingHandlers.cs#L42

foreach(GridViewSummaryItemState summaryItem in e.SummaryItems) {
    Aggregate aggregateType = GetAggregateType(summaryItem.SummaryType);
    CriteriaOperator aggregatedExpression = new OperandProperty(summaryItem.FieldName);

XPO_how-to-use-custom-sql-queries-as-a-data-source-in-xpo-via-common-table-expressions-cte-e3468/CS/Program.cs#L29

Console.WriteLine("=== Count for sine CTE ===");
Console.WriteLine("Count: {0}", uow.Evaluate<CteStructure_1>(new AggregateOperand(null, null, Aggregate.Count, null), null));
Console.WriteLine("=== Filtered count for sine CTE ===");

XPO_how-to-create-a-filter-with-an-aggregate-function-for-a-child-collection-e1329/CS/Form1.cs#L313

private void btnFiterStandard_Click(object sender, System.EventArgs e) {
    CriteriaOperator criteria = new AggregateOperand("Orders", Aggregate.Count) > 0;
    SetFilter(criteria);

XPO_how-to-create-and-use-the-joinoperand-using-linq-to-xpo-and-criteria-operators-e1883/CS/E1883/Program.cs#L20

CriteriaOperator op1 = new BinaryOperator(CreateExpression("^.Age"), CreateExpression("Age"), BinaryOperatorType.Equal);
op1 = new JoinOperand("Person", op1, Aggregate.Max, new OperandProperty("Age"));
op1 = new BinaryOperator(op1, new OperandProperty("Age"), BinaryOperatorType.Equal);

VB.NET

how-to-bind-an-aspnet-mvc-gridview-extension-to-a-table-with-an-unknown-schema-using-custo-t602001/VB/XPCustomBindingExample/XPO/XpoBindingHandlers.vb#L42

For Each summaryItem As GridViewSummaryItemState In e.SummaryItems
    Dim aggregateType As Aggregate = GetAggregateType(summaryItem.SummaryType)
    Dim aggregatedExpression As CriteriaOperator = New OperandProperty(summaryItem.FieldName)

XPO_how-to-use-custom-sql-queries-as-a-data-source-in-xpo-via-common-table-expressions-cte-e3468/VB/Program.vb#L33

Console.WriteLine("=== Count for sine CTE ===")
Console.WriteLine("Count: {0}", uow.Evaluate(Of CteStructure_1)(New AggregateOperand(Nothing, Nothing, Aggregate.Count, Nothing), Nothing))
Console.WriteLine("=== Filtered count for sine CTE ===")

XPO_how-to-create-a-filter-with-an-aggregate-function-for-a-child-collection-e1329/VB/Form1.vb#L299

Private Sub btnFiterStandard_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnFilterStandard.Click
    Dim criteria As CriteriaOperator = New AggregateOperand("Orders", Aggregate.Count) > 0
    SetFilter(criteria)

XPO_how-to-create-and-use-the-joinoperand-using-linq-to-xpo-and-criteria-operators-e1883/VB/E1883/Program.vb#L21

Dim op1 As CriteriaOperator = New BinaryOperator(CreateExpression("^.Age"), CreateExpression("Age"), BinaryOperatorType.Equal)
op1 = New JoinOperand("Person", op1, Aggregate.Max, New OperandProperty("Age"))
op1 = New BinaryOperator(op1, New OperandProperty("Age"), BinaryOperatorType.Equal)