使用EF的Database First中的連接字符串無法正常工作

Question

我通過EF創建了一個模型，但是當我嘗試執行查詢時，出現此錯誤：

如果在Code First模式下使用T4模板為Database First和Model First開發生成的代碼可能無法正常工作。 要繼續使用數據庫優先或模型優先，請確保在正在執行的應用程序的配置文件中指定了實體框架連接字符串。 若要使用從Database First或Model First生成的這些類以及Code First，請使用屬性或DbModelBuilder API添加任何其他配置，然后刪除引發此異常的代碼。

我向我的MVC項目添加了模型引用，並且向我的MVC項目添加了連接字符串，但存在相同的錯誤。

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

我從這行得到異常：

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

這是我的網絡配置

<?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

這是因為您嘗試將代碼優先樣式的連接字符串與模型/數據庫優先EF概念模型一起使用。

如果首先從數據庫生成了EF模型，則需要在msl ， ssdl和csdl文件的連接字符串中指定不同的模型方面。

您的連接字符串應如下所示：“ metadata = res：// /entityframework.Model1.csdl|res:// /entityframework.Model1.ssdl|res://*/entityframework.Model1.msl;provider=MySql.Data .MySqlClient;提供商連接字符串=“ server = localhost;用戶ID = myuserid;密碼= 12345678;數據庫=數據庫名稱”“

這篇MSDN文章很好地介紹了您首先需要從model / db的連接字符串中獲取什么：

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