Export (0) Print
Expand All

ObjectQuery<T> Constructor (String, ObjectContext, MergeOption)

Creates a new ObjectQuery<T> instance using the specified Entity SQL command as the initial query and the specified merge option.

Namespace:  System.Data.Objects
Assembly:  System.Data.Entity (in System.Data.Entity.dll)

public ObjectQuery(
	string commandText,
	ObjectContext context,
	MergeOption mergeOption
)

Parameters

commandText
Type: System.String

The Entity SQL query.

context
Type: System.Data.Objects.ObjectContext

The ObjectContext on which to execute the query.

mergeOption
Type: System.Data.Objects.MergeOption

Specifies how the entities that are retrieved through this query should be merged with the entities that have been returned from previous queries against the same ObjectContext.

When your application generates Entity SQL queries at runtime, you should be aware of any command length limitations of the data source. Entity SQL does not enforce limitations on the length of the command text in queries.

This example is based on the Adventure Works Sales Model. The ObjectQuery<T> is initialized with the specified query, ObjectContext, and MergeOption.

int productID = 900;
using (AdventureWorksEntities context =
    new AdventureWorksEntities())
{
    string queryString = @"SELECT VALUE product FROM 
        AdventureWorksEntities.Products AS product
        WHERE product.ProductID > @productID";

    ObjectQuery<Product> productQuery1 =
        new ObjectQuery<Product>(queryString,
            context, MergeOption.NoTracking);

    productQuery1.Parameters.Add(new ObjectParameter("productID", productID));

    ObjectQuery<DbDataRecord> productQuery2 =
        productQuery1.Select("it.ProductID");

    foreach (DbDataRecord result in productQuery2)
    {
        Console.WriteLine("{0}", result["ProductID"]);
    }
}

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5 SP1

.NET Framework Client Profile

Supported in: 4

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Show:
© 2014 Microsoft