Procedura: compilare una stringa di connessione EntityConnection (Entity Framework)

In questo argomento viene fornito un esempio di come compilare un oggetto EntityConnection.

Per eseguire il codice in questo esempio

1. Aggiungere il Modello Sales di AdventureWorks al progetto e configurare il progetto per l'utilizzo di Entity Framework . Per ulteriori informazioni, vedere Procedura: utilizzare la procedura guidata Entity Data Model (Entity Framework).

2. Nella tabella codici per l'applicazione aggiungere le istruzioni using seguenti (Imports in Visual Basic):

   Imports System
   Imports System.Collections.Generic
   Imports System.Collections
   Imports System.Data.Common
   Imports System.Data
   Imports System.IO
   Imports System.Data.SqlClient
   Imports System.Data.EntityClient
   Imports System.Data.Metadata.Edm
   

   using System;
   using System.Collections.Generic;
   using System.Collections;
   using System.Data.Common;
   using System.Data;
   using System.IO;
   using System.Data.SqlClient;
   using System.Data.EntityClient;
   using System.Data.Metadata.Edm;
   

Esempio

Nell'esempio seguente viene inizializzato l'oggetto System.Data.SqlClient.SqlConnectionStringBuilder per il provider sottostante, quindi viene inizializzato l'oggetto System.Data.EntityClient.EntityConnectionStringBuilder, che viene passato al costruttore di EntityConnection.

' Specify the provider name, server and database. 
Dim providerName As String = "System.Data.SqlClient"
Dim serverName As String = "."
Dim databaseName As String = "AdventureWorks"

' Initialize the connection string builder for the 
' underlying provider. 
Dim sqlBuilder As New SqlConnectionStringBuilder()

' Set the properties for the data source. 
sqlBuilder.DataSource = serverName
sqlBuilder.InitialCatalog = databaseName
sqlBuilder.IntegratedSecurity = True

' Build the SqlConnection connection string. 
Dim providerString As String = sqlBuilder.ToString()

' Initialize the EntityConnectionStringBuilder. 
Dim entityBuilder As New EntityConnectionStringBuilder()

'Set the provider name. 
entityBuilder.Provider = providerName

' Set the provider-specific connection string. 
entityBuilder.ProviderConnectionString = providerString

' Set the Metadata location. 
entityBuilder.Metadata = "res://*/AdventureWorksModel.csdl|res://*/AdventureWorksModel.ssdl|res://*/AdventureWorksModel.msl"
Console.WriteLine(entityBuilder.ToString())

Using conn As New EntityConnection(entityBuilder.ToString())
    conn.Open()
    Console.WriteLine("Just testing the connection.")
    conn.Close()
End Using

// Specify the provider name, server and database.
string providerName = "System.Data.SqlClient";
string serverName = ".";
string databaseName = "AdventureWorks";

// Initialize the connection string builder for the
// underlying provider.
SqlConnectionStringBuilder sqlBuilder =
    new SqlConnectionStringBuilder();

// Set the properties for the data source.
sqlBuilder.DataSource = serverName;
sqlBuilder.InitialCatalog = databaseName;
sqlBuilder.IntegratedSecurity = true;

// Build the SqlConnection connection string.
string providerString = sqlBuilder.ToString();

// Initialize the EntityConnectionStringBuilder.
EntityConnectionStringBuilder entityBuilder =
    new EntityConnectionStringBuilder();

//Set the provider name.
entityBuilder.Provider = providerName;

// Set the provider-specific connection string.
entityBuilder.ProviderConnectionString = providerString;

// Set the Metadata location.
entityBuilder.Metadata = @"res://*/AdventureWorksModel.csdl|
                            res://*/AdventureWorksModel.ssdl|
                            res://*/AdventureWorksModel.msl";
Console.WriteLine(entityBuilder.ToString());

using (EntityConnection conn =
    new EntityConnection(entityBuilder.ToString()))
{
    conn.Open();
    Console.WriteLine("Just testing the connection.");
    conn.Close();
}

Vedere anche

Attività

Procedura: utilizzare EntityConnection con un contesto dell'oggetto (Entity Framework)

Concetti

Provider EntityClient per Entity Framework