c# - 连接字符串不正确？错误 : An attempt to attach an auto-named database failed

Question

解决方案:将目录添加到 app.config 文件中的连接字符串和项目属性部分的 Settings.setting 文件中。我的工作连接字符串最终是 <Value Profile="(Default)">Data Source=(LocalDB)\v11.0;AttachDbFilename=F:\hi\prgrm\ProgramName\Database1.mdf;Integrated Security=True</Value>

一旦我运行我的程序，我得到以下错误:

An attempt to attach an auto-named database for file F:\Graded unit 2\SimplyRugby\LollipopUI\bin\Debug\Database1.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share.

导致错误发生的方法:

public bool CheckUsername(string username)
{
    var usernameResult = (from person in dbContext.Persons
                            where (person.Username == username)
                            select person.Username).FirstOrDefault(); 
                          //stores username if a username is found

    return !(string.IsNullOrEmpty(usernameResult));
    // if no correct user found from query return false else true
}

经过一番研究，显然是连接字符串错误。我对网上的一些建议进行了一些尝试，但我不太确定哪里不正确以及如何解决它，所以在过去五个小时左右的时间里我一直在兜圈子。

我的 app.config文件:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <connectionStrings>
        <add name="LollipopUI.Properties.Settings.Database1ConnectionString"
             connectionString="Data Source=(LocalDB)\v11.0;AttachDbFilename=|DataDirectory|\Database1.mdf;Integrated Security=True;"
             providerName="System.Data.SqlClient" />
    </connectionStrings>
    <startup> 
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
    </startup>
</configuration>

感谢您的宝贵时间。

Answer 1

尝试使用户实例属性为真

User Instance=True

在您的连接字符串中。

也可以引用这个related thread这表示您的连接字符串应如下所示:

<connectionStrings>
    <add name="Sales_DBEntities" 
         connectionString="metadata=res://*/Model1.csdl|res://*/Model1.ssdl|res://*/Model1.msl;provider=System.Data.SqlClient;provider connection string='server=YourServerNameHere;database=Sales_DB;integrated security=True;App=EntityFramework'" 
        providerName="System.Data.EntityClient" />
</connectionStrings>