EF 5迁移无法连接到我们的数据库，即使它在运行时运行良好

Question

We have three projects.

• Company.Domain (class library)
• Company.PublicWebsite (MVC3 Web Application)
• Company.InternalWebsite (MVC3 Web Application)

The two website projects have reference to Company.Domain .

Our EF 5 DbContext lives in Company.Domain.Data.EntityFramework and it looks like this:

using System.Data.Entity;
using Company.Domain.Data.EntityFramework.Entities;

namespace Company.Domain.Data.EntityFramework.
{
    public class CompanyEntities : DbContext
    {
        public DbSet<Notification> Notifications { get; set; }
        public DbSet<Report> Reports { get; set; }
        public DbSet<ReportSection> ReportSections { get; set; }
        public DbSet<ReportPage> ReportPages { get; set; }
        // brevity brevity
    }
}

We have enabled migrations and successfully used the tool in the past so I'm not sure why we are having issues now. Our migrations configuration lives in Company.Domain.Data.EntityFramework.Migrations and looks like this:

namespace Company.Domain.Data.EntityFramework.Migrations
{
    using System;
    using System.Data.Entity;
    using System.Data.Entity.Migrations;
    using System.Linq;
    using Company.Domain.Data.EntityFramework;

    public class Configuration : DbMigrationsConfiguration<CompanyEntities>
    {
        public Configuration()
        {
            MigrationsDirectory = @"Data\EntityFramework\Migrations";
            AutomaticMigrationsEnabled = false;
        }

        protected override void Seed(CompanyEntities context)
        {
            // empty at the moment
        }
    }
}

We then have an App.config file in the root of the Company.Domain project and it looks like this:

<?xml version="1.0" encoding="utf-8"?>
  <configuration>
    <configSections>
      <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=5.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
      <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
    </configSections>
    <connectionStrings>
      <add name="CompanyEntities" providerName="System.Data.SqlClient" connectionString="Data Source=devsql;Initial Catalog=CompanyEntities;uid=XXXXX;pwd=XXXXX;MultipleActiveResultSets=True;" />
    </connectionStrings>
    <entityFramework>
      <defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework">
        <parameters>
          <parameter value="v11.0" />
        </parameters>
      </defaultConnectionFactory>
    </entityFramework>
    <startup>
      <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
    </startup>
  </configuration>

Our database lives on another server on the network. I'm able to connect to it in SQL Server Management Studio and our applications are able to connect at runtime just fine. However, when I try to run add-migration or even update-database I get the following error:

http://content.screencast.com/users/Chevex/folders/Snagit/media/80fbfd6a-4956-407f-b88f-d5a53a9e5feb/03.21.2013-10.25.png

System.Data.ProviderIncompatibleException: An error occurred while getting provider information from the database. This can be caused by Entity Framework using an incorrect connection string. Check the inner exceptions for details and ensure that the connection string is correct. ---> System.Data.ProviderIncompatibleException: The provider did not return a ProviderManifestToken string. ---> System.Data.SqlClient.SqlException: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections.

I've even reverted my changes to the model and then ran update-database just to see if it would say 'database is on latest migration' but I still got the above error. I've poured over the connection string in App.config over and over. I cannot figure out why migrations won't connect but both of our website projects work just fine at runtime. Migrations have worked in the past. Below are the migrations in solution explorer compared with those found in the __MigrationHistory table in the database.

http://content.screencast.com/users/Chevex/folders/Snagit/media/7abeaa46-ff0f-4817-a0d7-1adb086e8f0c/03.21.2013-10.30.png

http://content.screencast.com/users/Chevex/folders/Snagit/media/3c6ac54d-f63d-417f-9253-39b6a8fea85d/03.21.2013-10.32.png

It looks like I should be able to run update-database and have it tell me that it is up to date, but I get that error instead.

As I understand it, migrations shouldn't be paying any attention to our two website projects when I'm running migrations commands, but I poured over their Web.config files as well just in case. The connection strings are identical to App.config.

Edit:

I've even tried completely uninstalling and removing the EF 5 package from the projects and reinstalling. Same issue >:(

Answer 1

您的启动项目是否包含web.config或app.config作为EF使用start项目作为连接字符串的源

Answer 2

OK, so that didn't work for me at first :(

Then after a cup of coffee and adding StartUPProjectName to it, it did! Try:

Update-Database -StartUpProjectName MYPROJECT.NAME -Script

Try to point it to a start Up project where you web.config/app.config lives

Answer 3

If you get the help for enable migrations in the Package Manager Console

Get-Help enable-migrations -detailed

You can find this documentation for the -StartupProjectName option:

-StartUpProjectName

  Specifies the configuration file to use for named connection strings. If omitted, the specified project's configuration file is used. 

The doc it's a little confusing, but it means that if you use this option to specify a project name, migrations will look for the connection string in the config file of the specified project. (The config file can be web.config or app.config ).

If you're creating a web app, most probably the connection string will be in its web.config , so you have to specify the web app project. If it's other kind of project, the connection string will be in an app.config file of a class library or whatever, and you'll have to specify that project.

Besides it's recommended that you use a constructor for your DbContext class that specifies the name of the connection string, ie

public class CompanyEntities : DbContext
{
    public CompanyEntities()
       :base("ConnectionStringName")
    {
         ...
    }
....
}

In this way you don't depend on default connection strings, which may be confusing.

Answer 4

You say you can connect via SQL Management Studio, but my guess is you use Windows Authentication for that, and not the uid=XXXXX;pwd=XXXXX; supplied in your connection string.

Try to get Management Studio to connect using that userid and password.

Also, that account might be locked out (if it is an Active Directory account).

Answer 5

This sounds eerily like a problem a client of mine had. It had to do with something having mucked up the DbProviders section of machine.config. He put the details here: http://social.msdn.microsoft.com/Forums/en-US/adodotnetentityframework/thread/f2a19487-6d38-4a79-a809-d3efe4c9d9fe (it's the Adam Scholz answer to his boss' question. :) )

Julie

Answer 6

May be this is solved already but i got it solved by setting the start up project in my solution to the entity dll project ( having app.config file ). I did set the "Default project" in Package Manager Console window to the correct entity dll project but that did't work. For details

Entity Framework 6 with SQL Server 2012 gives System.Data.Entity.Core.ProviderIncompatibleException system-data-entity-core-providerin

Answer 7

If your solution has multiple projects, try setting the Startup Project for the solution to the project that contains the Web.Config or App.Config file that contains the settings for EF.

I had a solution with a Web project and seperate project (Data.Models) for my models. All was well until I added a console application to the solution. As soon as I set that to be the startup project, EF Migrations would fail.

Also, if multiple projects in the solution have migrations enabled, always run the Update-Database on each project after you do a Add-Migration. My web project had a pending migration, and the migrations failed weirdly on the second project because of the pending migration in the first.