我应该如何从WCF服务解决方案访问SQL Server？

  <add name="MyDatabaseConnectionString" connectionString="Data Source=YOUR_SERVER_NAME;Initial Catalog=YOUR_DATABASE_NAME;User ID=YOUR_USERNAME;Password=YOUR_PASSWORD" providerName="System.Data.SqlClient" />
</connectionStrings>

using System.Linq;
using System.Data.Objects;
using MyWCFService.MyEntityModel;

public class DataAccess
{
    private MyEntityModelContainer _context = new MyEntityModelContainer();

    public List<MyData> GetData()
    {
        return _context.MyData.ToList();
    }
}

public class MyService : IMyService
{
    private DataAccess _dataAccess = new DataAccess();

    public List<MyData> GetData()
    {
        return _dataAccess.GetData();
    }
}

<behaviors>
 <serviceBehaviors>
    <behavior name="MyServiceBehavior">
      <dataContractSerializer maxItemsInObjectGraph="2147483647" />
     <serviceMetadata httpGetEnabled="true" />
     <serviceDebug includeExceptionDetailInFaults="true" />
    </behavior>
  </serviceBehaviors>
</behaviors>