无法在 C# 中创建连接字符串 [英] Can't make a connection string in c#

问题描述

我是 C# 新手，了解不多！

I'm new to C# and don't know much!

我在 C# 2012 中创建了一个本地数据库，并想建立一个连接.我用它的向导测试了连接，它说成功连接到数据库.

I have created a local database in C# 2012 and want to make a connection to it. I tested connection with its wizard and it said successfully connected to database.

所以我将连接字符串地址复制到我的代码中，但在运行几秒钟后，我出现了异常错误！

So I copied connection string address to my code but after few seconds of running i have and exception error!

我不知道问题出在哪里！

I don't know where the problem is!

这是我的代码:

System.Data.SqlClient.SqlConnection myConnection;

private void Form1_Load(object sender, EventArgs e)
{
    myConnection = new System.Data.SqlClient.SqlConnection();
    myConnection.ConnectionString = "Data Source=(LocalDB)\v11.0;AttachDbFilename=C:\\Users\\jack\\Documents\\Visual Studio 2012\\Projects\\dictionary\\dictionary\\dictionaryDb.mdf;Integrated Security=True;Connect Timeout=30";
    myConnection.Open();

    MessageBox.Show("successfully connected!");
}

这是异常错误:

与 SQL Server 建立连接时发生与网络相关或特定于实例的错误.服务器未找到或无法访问.验证实例名称是否正确以及 SQL Server 是否配置为允许远程连接.(提供程序:命名管道提供程序，错误:40 - 无法打开与 SQL Server 的连接)

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: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)

我的另一个问题是:SQL Server Express 和 C# 中的本地数据库有区别吗?

And my other question is: is it differences between SQL Server Express and local database in C#?

谢谢

推荐答案

你好像漏掉了 (LocalDB) 和 v11.0 之间的一个反斜杠 \:

It seems like you miss one backslash \ between (LocalDB) and v11.0:

myConnection.ConnectionString = "Data Source=(LocalDB)\\v11.0;AttachDbFilename=C:\\Users\\jack\\Documents\\Visual Studio 2012\\Projects\\dictionary\\dictionary\\dictionaryDb.mdf;Integrated Security=True;Connect Timeout=30";

一个反斜杠将被视为转义字符，两个反斜杠\\将被视为反斜杠.或者，执行此操作(使用 @)以使您的字符串字符更清晰:

One back slash will be consider as escape character, two backslashes \\ will be treated as backslash. Alternative, do this (using @) to make your string character clearer:

myConnection.ConnectionString = @"Data Source=(LocalDB)\v11.0;AttachDbFilename=C:\Users\jack\Documents\Visual Studio 2012\Projects\dictionary\dictionary\dictionaryDb.mdf;Integrated Security=True;Connect Timeout=30";

您还可以在 app.config 中指定您的 connectionString<add name="DefautConnection" connectionString="Data Source=(LocalDB)\v11.0;AttachDbFilename=C:\Users\jack\Documents\Visual Studio 2012\Projects\dictionary\dictionary\dictionaryDb.mdf;Integrated Security=True;Connect Timeout=30;" .. 等等，这种情况并不少见.

You could also specify your connectionString in your app.config <connectionStrings> <add name="DefautConnection" connectionString="Data Source=(LocalDB)\v11.0;AttachDbFilename=C:\Users\jack\Documents\Visual Studio 2012\Projects\dictionary\dictionary\dictionaryDb.mdf;Integrated Security=True;Connect Timeout=30;" .. and so on which is not uncommon.

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