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ObjectContext Constructor (String)

Initializes a new instance of the ObjectContext class with the given connection string and default entity container name.

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

public ObjectContext(
	string connectionString
)

Parameters

connectionString
Type: System.String

The connection string, which also provides access to the metadata information.

ExceptionCondition
ArgumentNullException

The connectionString is null.

ArgumentException

The connectionString is invalid.

-or-

The metadata workspace is not valid.

The connectionString is a string that contains information that is required to access an Entity Data Model (EDM) and to connect to a data source. The EntityConnectionStringBuilder class can be used to correctly format the string.

The Entity Data Model tools generate a named connection string that is stored in the application's configuration file. This named connection string can be supplied instead of the connectionString parameter when instantiating the ObjectContext class.

The example in this topic is based on the Adventure Works Sales Model. The example shows how to construct an ObjectContext.

// Create the ObjectContext.
ObjectContext context =
    new ObjectContext("name=AdventureWorksEntities");

// Set the DefaultContainerName for the ObjectContext.
context.DefaultContainerName = "AdventureWorksEntities";

ObjectQuery<Product> query = new ObjectQuery<Product>("Product", context);

// Iterate through the collection of Products. 
foreach (Product result in query)
    Console.WriteLine("Product Name: {0}", result.Name);

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

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

.NET Framework

Supported in: 3.5 SP1

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