C# web.config中的connectionstring错误:System.InvalidOperationException:实例失败
我正在使用Visual Studio社区版和C#和SQL Server Express 2014为数据库开发一个应用程序 当我在C# web.config中的connectionstring错误:System.InvalidOperationException:实例失败,c#,asp.net,web-config,C#,Asp.net,Web Config,我正在使用Visual Studio社区版和C#和SQL Server Express 2014为数据库开发一个应用程序 当我在Web.config文件中定义连接字符串时,如下所示: <connectionStrings> <add name="connect" connectionString="data source=PTW\SQLEXPRESS; Database=Mydb; integrated security=SSPI"
Web.config
文件中定义连接字符串时,如下所示:
<connectionStrings>
<add name="connect"
connectionString="data source=PTW\SQLEXPRESS; Database=Mydb; integrated security=SSPI"
providerName="System.Data.SqlClient"/>
</connectionStrings>
我得到一个错误:
System.InvalidOperationException:实例失败
但是,当我在表单中定义连接字符串时,不会出现错误,并且会建立连接
我如何解决这个问题
以下是web.config文件中的内容:
<configuration>
<connectionStrings>
<add name="connect"
connectionString="data source=PTW\SQLEXPRESS; Database=Mydb; integrated security=SSPI"
providerName="System.Data.SqlClient"/>
</connectionStrings>
<system.web>
<compilation debug="true" targetFramework="4.5.2"/>
<httpRuntime targetFramework="4.5.2"/>
</system.web>
<system.codedom>
<compilers>
<compiler language="c#;cs;csharp" extension=".cs"
type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.CSharpCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"
warningLevel="4" compilerOptions="/langversion:6 /nowarn:1659;1699;1701"/>
<compiler language="vb;vbs;visualbasic;vbscript" extension=".vb"
type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.VBCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"
warningLevel="4" compilerOptions="/langversion:14 /nowarn:41008 /define:_MYTYPE=\"Web\" /optionInfer+"/>
</compilers>
</system.codedom>
</configuration>
问题来自SQL Server端,刚从microsoft(hotfix v4.microsoft.com)安装了SQL Server update(4),就这样,完成了。什么是“ASP.net社区版”?另外,您的异常是来自问题中显示的代码行还是其他行?它是visual studio社区版2015。当连接尝试使用以下代码打开时,会出现错误:con.open();然后您需要提供该代码,因为它甚至可能与您的连接字符串无关。请创建一个。我添加了完整的代码
<configuration>
<connectionStrings>
<add name="connect"
connectionString="data source=PTW\SQLEXPRESS; Database=Mydb; integrated security=SSPI"
providerName="System.Data.SqlClient"/>
</connectionStrings>
<system.web>
<compilation debug="true" targetFramework="4.5.2"/>
<httpRuntime targetFramework="4.5.2"/>
</system.web>
<system.codedom>
<compilers>
<compiler language="c#;cs;csharp" extension=".cs"
type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.CSharpCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"
warningLevel="4" compilerOptions="/langversion:6 /nowarn:1659;1699;1701"/>
<compiler language="vb;vbs;visualbasic;vbscript" extension=".vb"
type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.VBCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"
warningLevel="4" compilerOptions="/langversion:14 /nowarn:41008 /define:_MYTYPE=\"Web\" /optionInfer+"/>
</compilers>
</system.codedom>
</configuration>
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.SqlClient;
using System.Configuration;
namespace GlobalCS
{
public partial class Connect : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Button1_Click(object sender, EventArgs e)
{
string cs = ConfigurationManager.ConnectionStrings["connect"].ConnectionString;
using (SqlConnection con = new SqlConnection(cs))
{
con.Open();
Label1.Text = "Connected";
}
}
}
}