使用EF的Database First中的连接字符串无法正常工作

Question

我通过EF创建了一个模型，但是当我尝试执行查询时，出现此错误：

如果在Code First模式下使用T4模板为Database First和Model First开发生成的代码可能无法正常工作。 要继续使用数据库优先或模型优先，请确保在正在执行的应用程序的配置文件中指定了实体框架连接字符串。 若要使用从Database First或Model First生成的这些类以及Code First，请使用属性或DbModelBuilder API添加任何其他配置，然后删除引发此异常的代码。

我向我的MVC项目添加了模型引用，并且向我的MVC项目添加了连接字符串，但存在相同的错误。

<connectionStrings>
 <add name="EducationDBEntities" connectionString="Data Source=.;
     Initial Catalog=EducationDB;User ID=sa;Password=ehsanakbar"
     providerName="System.Data.SqlClient" />
</connectionStrings>

我从这行得到异常：

  protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        throw new UnintentionalCodeFirstException();
    }

这是我的网络配置

<?xml version="1.0" encoding="utf-8"?>



      <configuration>
  <configSections>
 <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
    <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=5.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
  </configSections>
<connectionStrings>
  <add name="EducationDBEntities" connectionString="Data Source=.;Initial Catalog=EducationDB;User ID=sa;Password=ehsanakbar"
    providerName="System.Data.SqlClient" />
  </connectionStrings>
  <appSettings>
    <add key="webpages:Version" value="2.0.0.0" />
    <add key="webpages:Enabled" value="false" />
    <add key="PreserveLoginUrl" value="true" />
    <add key="ClientValidationEnabled" value="true" />
    <add key="UnobtrusiveJavaScriptEnabled" value="true" />
  </appSettings>
  <system.web>
    <compilation debug="true" targetFramework="4.5" />
    <httpRuntime targetFramework="4.5" />
    <authentication mode="Forms">
      <forms loginUrl="~/Account/Login" timeout="2880" />
    </authentication>
    <pages>
      <namespaces>
        <add namespace="System.Web.Helpers" />
        <add namespace="System.Web.Mvc" />
        <add namespace="System.Web.Mvc.Ajax" />
        <add namespace="System.Web.Mvc.Html" />
        <add namespace="System.Web.Optimization" />
        <add namespace="System.Web.Routing" />
        <add namespace="System.Web.WebPages" />
      </namespaces>
    </pages>
  </system.web>
  <system.webServer>
    <validation validateIntegratedModeConfiguration="false" />
    <handlers>
      <remove name="ExtensionlessUrlHandler-ISAPI-4.0_32bit" />
      <remove name="ExtensionlessUrlHandler-ISAPI-4.0_64bit" />
      <remove name="ExtensionlessUrlHandler-Integrated-4.0" />
      <add name="ExtensionlessUrlHandler-ISAPI-4.0_32bit" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness32" responseBufferLimit="0" />
      <add name="ExtensionlessUrlHandler-ISAPI-4.0_64bit" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework64\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness64" responseBufferLimit="0" />
      <add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
    </handlers>
  </system.webServer>
  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-2.0.0.0" newVersion="2.0.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-4.0.0.0" newVersion="4.0.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.WebPages" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-2.0.0.0" newVersion="2.0.0.0" />
      </dependentAssembly>
    </assemblyBinding>
  </runtime>
  <entityFramework>
    <defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework">
      <parameters>
        <parameter value="v11.0" />
      </parameters>
    </defaultConnectionFactory>
  </entityFramework>
</configuration>

Answer 1

这是因为您尝试将代码优先样式的连接字符串与模型/数据库优先EF概念模型一起使用。

如果首先从数据库生成了EF模型，则需要在msl ， ssdl和csdl文件的连接字符串中指定不同的模型方面。

您的连接字符串应如下所示：“ metadata = res：// /entityframework.Model1.csdl|res:// /entityframework.Model1.ssdl|res://*/entityframework.Model1.msl;provider=MySql.Data .MySqlClient;提供商连接字符串=“ server = localhost;用户ID = myuserid;密码= 12345678;数据库=数据库名称”“

这篇MSDN文章很好地介绍了您首先需要从model / db的连接字符串中获取什么：

https://msdn.microsoft.com/en-us/data/jj592674