EntityDataSource.Where Property

Definition

Namespace:

System.Web.UI.WebControls

Assembly:

System.Web.Entity.dll

Gets or sets the Entity SQL expression that specifies how to filter the query results.

public:
 property System::String ^ Where { System::String ^ get(); void set(System::String ^ value); };

public string Where { get; set; }

member this.Where : string with get, set

Public Property Where As String

Property Value

String

The WHERE clause.

Implements

Where

Examples

The XML markup in the following example, in an .aspx file, retrieves a value from a control and passes it as a parameter to the Where property.

<asp:EntityDataSource ID="SalesOrderHeader" runat="server"
  ConnectionString="name=AdventureWorksEntities"
  DefaultContainerName="AdventureWorksEntities" EnableDelete="True"
  EnableInsert="True" EnableUpdate="True" EntitySetName="SalesOrderHeader"
  EntityTypeFilter="" OrderBy="it.TotalDue DESC" Select=""
   Where="it.OnlineOrderFlag = TRUE AND it.TotalDue > @ordercost">
  <WhereParameters>
    <asp:ControlParameter ControlID="costLimit" DbType="Int32"
      DefaultValue="2500" Name="ordercost" PropertyName="Text" />
  </WhereParameters>
</asp:EntityDataSource>

The previous XML example is the same as the following ObjectQuery<T> named onlineOrders:

ObjectQuery<SalesOrderHeader> onlineOrders =
      context.SalesOrderHeader
       .Where("it.OnlineOrderFlag = TRUE AND it.TotalDue > @ordercost",
         new ObjectParameter("ordercost", orderCost))
        .OrderBy("it.TotalDue DESC");

Remarks

The Where property of the EntityDataSource control is a string that represents a WHERE clause that is the predicate of an Entity SQL query. This string is passed, without modification, to an ObjectQuery<T> that is executed by the Entity Framework. This query is the source of the data regulated by the EntityDataSource control. The string supplied to the Where property uses the same format as the string that is passed to the Where method of ObjectQuery<T>. For examples of how to use the WHERE clause to filter a query, see How to: Filter Data.

To filter query results by equating an entity type property to an expression, see information about the AutoGenerateWhereClause property.