Entity framework 使用数据库模式无法连接到服务器

Question

我首先尝试使用 db 通过 db 实例连接，我创建了一个连接

 <add name="Entities" 
      connectionString="metadata=res://*/Models.ModelCmarket.csdl|res://*/Models.ModelCmarket.ssdl|res://*/Models.ModelCmarket.msl;provider=System.Data.SqlClient;provider connection string=&quot;data source=(localdb)\v12.0;initial catalog=Cevaheer;integrated security=True;trustservercertificate=False;multisubnetfailover=True;MultipleActiveResultSets=True;multipleactiveresultsets=True;App=EntityFramework&quot;" 
      providerName="System.Data.EntityClient" />

而且我总是出错 -

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. (provider: SQL Network Interfaces, error: 50 - Local Database Runtime error occurred. The specified LocalDB instance does not exist.)

但如果我尝试

<add name="CevhermarketEntities" 
     connectionString="Data source=(localdb)\v12.0;initial catalog=Cevaheer;integrated security=True;trustservercertificate=False;multisubnetfailover=True;MultipleActiveResultSets=True;user id=dbuser;password=flexsin@123!;multipleactiveresultsets=True;"
     providerName="System.Data.SqlClient" />

我可以连接，也可以从 VS sql 服务器资源管理器和 SSMS 连接。

Answer 1

首先 - 有 4 个问题可能导致 常见 LocalDb SqlExpress Sql 服务器连接错误 SQL Network Interfaces, error: 50 - Local Database Runtime error occurred，在你开始之前你 need to rename the v11 or v12 to (localdb)\mssqllocaldb

你没有 services running
你没有 firelwall ports here 配置
您的安装 issue/corrupt（以下步骤有助于您顺利开始）
你没有rename the V11 or 12 to mssqllocaldb

我发现最简单的方法是执行以下操作 - 我已附上图片和步骤以寻求帮助。

首先验证您安装了哪个实例，您可以通过检查注册表 和 通过运行命令

cmd> Sqllocaldb.exe i
cmd> Sqllocaldb.exe s "whicheverVersionYouWantFromListBefore" 如果此步骤失败，您可以使用选项 d cmd> Sqllocaldb.exe d "someDb"
cmd> Sqllocaldb.exe c "createSomeNewDbIfyouWantDb" 创建 - 图片有误
cmd> Sqllocaldb.exe start "createSomeNewDbIfyouWantDb"

Entity framework 使用数据库模式无法连接到服务器

Entity framework with db mode cannot connect to server

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