c# – Code-First,当我进行启用迁移时,我得到“在程序集’DOC’中找不到上下文类型”

2023年11月27日 510次阅读

我正在使用Code-First,使用标准模板创建一个网站,然后继续将表添加到主applicationDBContext,但是现在当我在Package Manager Console中启用Enable-Migrations时,我得到了

No context type was found in the assembly ‘DOC’.

当我使用完整路径时：

ContextTypeName Option enable-migrations -ContextTypeName DOC.Migrations.Configuration

……我明白了：

Migrations have already been enabled in project ‘DOC’. To overwrite the existing migrations configuration, use the -Force parameter.

当我说 – Force时,它说

Code First Migrations enabled for project DOC.

但是当我尝试添加迁移时,我得到了

Error CS0311 The type ‘DOC.Migrations.Configuration’ cannot be used as type parameter ‘TContext’ in the generic type or method ‘DbMigrationsConfiguration’. There is no implicit reference conversion from ‘DOC.Migrations.Configuration’ to ‘System.Data.Entity.DbContext’. DOC xxxxxxx\DOC\Migrations\Configuration.cs.

当我检查Configuration.cs文件时,它改为：

internal sealed class Configuration : DbMigrationsConfiguration

…至：

internal sealed class Configuration : DbMigrationsConfiguration

…导致项目无法构建

我管理的唯一一次通过将实体框架从6.1.3降级到6.1.2然后重新升级来实现这一点.

有时,我必须升级和降级几次,关闭VS并重新打开,然后它才能工作.

这个问题有方法解决吗？它非常烦人.

《c# – Code-First,当我进行启用迁移时,我得到“在程序集’DOC’中找不到上下文类型”》

我也注意到我的DbContext类派生自IdentityDBContext,这样可以吗？我知道通常你是从DbContext派生出来的,但是自从我使用向导启动项目后,它自动创建了这个,我只是将其他表添加到它.

《c# – Code-First,当我进行启用迁移时,我得到“在程序集’DOC’中找不到上下文类型”》

我的web.config

    <?xml version="1.0" encoding="utf-8"?>
<!--
  For more information on how to configure your ASP.NET application, please visit
  http://go.microsoft.com/fwlink/?LinkId=301880
  -->
<configuration>
  <configSections>
    <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />

  <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 --><!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 --><!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 --><!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 --><!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 --><!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 --><!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 --><!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 --><!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 --><!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 --></configSections>
  <connectionStrings>
    <add name="DefaultConnection" connectionString="data source=localhost\SQLTEST;initial catalog=DOC;User Id=xxx;Password=xxxx;multipleactiveresultsets=True;application name=EntityFramework" providerName="System.Data.SqlClient" />
    <!--<add name="DefaultConnection" connectionString="data source=zzzzz;initial catalog=DOC;User Id=zzzzzz;Password=zzzzz;multipleactiveresultsets=True;application name=EntityFramework" providerName="System.Data.SqlClient" />-->
  </connectionStrings>
  <appSettings>
    <add key="webpages:Version" value="3.0.0.0" />
    <add key="webpages:Enabled" value="false" />
    <add key="ClientValidationEnabled" value="true" />
    <add key="UnobtrusiveJavaScriptEnabled" value="true" />
  </appSettings>
  <!--
    For a description of web.config changes see http://go.microsoft.com/fwlink/?LinkId=235367.

    The following attributes can be set on the <httpRuntime> tag.
      <system.Web>
        <httpRuntime targetFramework="4.5.2" />
      </system.Web>
  -->
  <system.web>
    <authentication mode="None" />
    <compilation debug="true" targetFramework="4.5.2" />
    <httpRuntime targetFramework="4.5" />
  </system.web>
  <system.webServer>
    <security>
      <requestFiltering>
        <requestLimits maxAllowedContentLength="1073741824" />
      </requestFiltering>
    </security>
    <modules>
      <remove name="FormsAuthentication" />
    </modules>
    <handlers>
      <remove name="ExtensionlessUrlHandler-Integrated-4.0" />
      <remove name="OPTIONSVerbHandler" />
      <remove name="TRACEVerbHandler" />
      <add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="*" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
    </handlers>
  </system.webServer>
  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <assemblyIdentity name="Microsoft.Owin" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="Microsoft.Owin.Security.OAuth" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="Microsoft.Owin.Security.Cookies" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="Microsoft.Owin.Security" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="Newtonsoft.Json" culture="neutral" publicKeyToken="30ad4fe6b2a6aeed" />
        <bindingRedirect oldVersion="0.0.0.0-9.0.0.0" newVersion="9.0.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Optimization" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-1.1.0.0" newVersion="1.1.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="WebGrease" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="0.0.0.0-1.6.5135.21930" newVersion="1.6.5135.21930" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="Microsoft.AspNet.Identity.Core" publicKeyToken="31bf3856ad364e35" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-2.0.0.0" newVersion="2.0.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="EntityFramework.MappingAPI" publicKeyToken="7ee2e825d201459e" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-6.1.0.9" newVersion="6.1.0.9" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.WebPages" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-5.2.3.0" newVersion="5.2.3.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="Antlr3.Runtime" publicKeyToken="eb42632606e9261f" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-3.5.0.2" newVersion="3.5.0.2" />
      </dependentAssembly>
    </assemblyBinding>
  </runtime>
  <entityFramework>
    <defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework" />
    <providers>
      <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
    </providers>
  </entityFramework>
</configuration>

最佳答案 您正在混淆启用迁移和添加迁移的参数.

enable-migrations具有上下文类型名称.您正在指定配置名称,而不是上下文.

enable-migrations -ContextTypeName DOC.Models.ApplicationDbContext

然后添加：

add-migration MyMigrationName -ConfigurationTypeName DOC.Migrations.Configuration

我不确定你甚至需要参数,因为看起来你有一个项目.这是command reference

您从IdentityDbContext继承并不重要.此外,EF没有版本6.3和6.4,它是6.1.3或EF Core.

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