Error when using Code First in web service “System.Data.ProviderIncompatibleException: The provider did not return a ProviderManifestToken string.”

问题

I'm using Code First. Everything works just fine (inserts, updates, selects) everything is tested. The problem comes when I try to use the web services. I get the error "System.Data.ProviderIncompatibleException: The provider did not return a ProviderManifestToken string.". Looking at the inner exception I get this message "Could not determine storage version; a valid storage connection or a version hint is required.".

The web service Code:

/// <summary>
/// Summary description for UserServices
/// </summary>
[WebService(Namespace = "http://localhost:3955/WebServices/UserServices")]
//[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
//[System.ComponentModel.ToolboxItem(false)]
// To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line. 
[System.Web.Script.Services.ScriptService]
public class UserServices : System.Web.Services.WebService
{

    [WebMethod]
    public bool LoginControlPanelUser(string user, string password)
    {
        if(Membership.ValidateUser(user, password))
        {
            return DbUsersDAO.HasAuthenticationType(user, password);
        }
        return false;
    }
}

The DAO code:

    public static bool HasAuthenticationType(string user, string authenticationTypeCode)
    {
        try
        {
            using (VirtusCloudCoreContext ctx = new VirtusCloudCoreContext())
            {
                DBUser User = ctx.DBUsers.SingleOrDefault(u => u.Login.Equals(user) && u.Active.Equals(true));
                if (User != null)
                {
                        return DBAuthenticationTypesDAO.GetById(User.DBAuthenticationTypeId).Name.Equals("Admin");
                }
            }
            return false;

        }
        catch (Exception ex)
        {
            ErrorsHelper.InsertError(ex);
            throw ex;
        }
    }

The Context class:

    public VirtusCloudCoreContext()
    {
        Database.SetInitializer<VirtusCloudCoreContext>(new VirtusCloudCoreContextInitializer());
        this.Database.Connection.ConnectionString = "Data Source=localhost\SQLEXPRESS;Database=DatabaseName;User Id=******;Password=*******;" ;

    }

I get the exception when I try to get the user.... Any ideas?

回答1:

This error occurs often when the connection string is wrong but I think in your case it's because you're trying to manually set the connection string.

Try making your context inherit from DbContext and take a connection string in your constructor which it passes through to the base constructor, like this:

public class VirtualCloudCoreContext : DbContext {
     public VirtualCloudCoreContext(string connectionString) 
             : base (connectionString) {
     }
 }

回答2:

I'm using a new DB-generated EDMX in VS2012 Web Project with a separate class file - both projects have EF 6.1.1 installed. Even though I'm using SQL 2012, I had to edit the EDMX file directly and change it to ProviderManifestToken="2008" from 2012.

Not sure if related to Telerik Grid/EntityDataSource or not. More mention of this issue here but related to VS2013.

来源：https://stackoverflow.com/questions/8563048/error-when-using-code-first-in-web-service-system-data-providerincompatibleexce

标签

web-services

code-first