ObjectQuery<T>::Select Method (String^, array<ObjectParameter^>^)
Limits the query results to only the properties that are defined in the specified projection.
Assembly: System.Data.Entity (in System.Data.Entity.dll)
public: ObjectQuery<DbDataRecord^>^ Select( String^ projection, ... array<ObjectParameter^>^ parameters )
Parameters
- projection
-
Type:
System::String^
The list of selected properties that defines the projection.
- parameters
-
Type:
array<System.Data.Objects::ObjectParameter^>^
Zero or more parameters that are used in this method.
Return Value
Type: System.Data.Objects::ObjectQuery<DbDataRecord^>^A new ObjectQuery<T> instance of type DbDataRecord that is equivalent to the original instance with SELECT applied.
| Exception | Condition |
|---|---|
| ArgumentNullException | projection is null. -or- parameters is null. |
| ArgumentException | The projection is an empty string. |
Select applies the projection specified by the projection parameter. The ObjectQuery<T> returned by the Select method is always a row type of DbDataRecord. Use the SelectValue<TResultType> method to return values that are simple types, entity types, or complex types. For more information, see Object Queries.
When a navigation property is included in the projection, the query results include a collection of nested DbDataRecord objects. For more information, see How to: Navigate Relationships Using Navigation Properties.
This example is based on the AdventureWorks Sales Model. The example creates a new ObjectQuery<T> whose results are data records that contain the ProductID fields of the results of this query.
Available since 3.5