IObjectSpace.CreateDataView(Type, IList<DataViewExpression>, CriteriaOperator, IList<SortProperty>) Method

Returns a list of data records retrieved from a database without loading complete business classes (a data view).

Namespace: DevExpress.ExpressApp

Assembly: DevExpress.ExpressApp.v22.2.dll

NuGet Package: DevExpress.ExpressApp

Declaration

C#

IList CreateDataView(
    Type objectType,
    IList<DataViewExpression> expressions,
    CriteriaOperator criteria,
    IList<SortProperty> sorting
)

VB.NET

Function CreateDataView(
    objectType As Type,
    expressions As IList(Of DataViewExpression),
    criteria As CriteriaOperator,
    sorting As IList(Of SortProperty)
) As IList

Parameters

Name	Type	Description
objectType	Type	The Type of requested objects.
expressions	IList<DataViewExpression>	An IList<DataViewExpression> list that specifies data view column names and expressions used to compute column values. These column names can be used for sorting data view via the sorting parameter.
criteria	CriteriaOperator	A CriteriaOperator object that specifies criteria associated with the data view.
sorting	IList<SortProperty>	An IList<SortProperty> collection whose elements identify the sorted columns within the data view.

Returns

Type	Description
IList	An IList object that returns a lightweight list of data records.

Remarks

This method does not return real objects. Instead, a lightweight read-only list of data records that can be viewed much more quickly than a real objects collection is returned.

This method result can be directly cast to XafDataView.

C#

List<DataViewExpression> dataViewExpressions = new List<DataViewExpression>();
dataViewExpressions.Add(
    new DataViewExpression("ID", new OperandProperty("ID")));
dataViewExpressions.Add(new DataViewExpression(
    "Name.UpperCase", new FunctionOperator(FunctionOperatorType.Upper, new OperandProperty("Name"))));
dataViewExpressions.Add(new DataViewExpression(
    "Count", new AggregateOperand("Sales", Aggregate.Count)));
CriteriaOperator criteria = new BinaryOperator(
    "Sales.Count", 0, BinaryOperatorType.Greater);
SortProperty[] sorting = new SortProperty[] { 
    new SortProperty("Name", SortingDirection.Ascending)
};
XafDataView dataView = (XafDataView)objectSpace.CreateDataView(
    typeof(Sale), dataViewExpressions, criteria, sorting);

VB.NET

Dim dataViewExpressions As New List(Of DataViewExpression)()
dataViewExpressions.Add(New DataViewExpression( _
"ID", New OperandProperty("ID")))
dataViewExpressions.Add(New DataViewExpression( _
"Name.UpperCase", New FunctionOperator(FunctionOperatorType.Upper, New OperandProperty("Name"))))
dataViewExpressions.Add(New DataViewExpression( _
"Count", New AggregateOperand("Sales", Aggregate.Count)))
Dim criteria As CriteriaOperator = New BinaryOperator("Sales.Count", 0, BinaryOperatorType.Greater)
Dim sorting() As SortProperty = { New SortProperty("Name", SortingDirection.Ascending) }
Dim dataView As XafDataView = CType(objectSpace.CreateDataView( _
    GetType(Sale), dataViewExpressions, criteria, sorting), XafDataView)