如果你是在C＃，你可以创建一个应用程序配置文件（App.config），它将有连接字符串与其名称。

If you are in C#, you can create an application config file (App.config), which will be having the connection string with its name.

这是示例app.config中的代码

this is sample code in the app.config

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <configSections>
  </configSections>
    <connectionStrings>
       <add name="myConnString" connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=D:\AppsTest\Nov17RoomBooking\dbRoomBooking.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True"
    providerName="System.Data.SqlClient" />
    </connectionStrings>
</configuration>

然后，您的代码应如下所示：

Then Your code should look like this:

private static string sqlConnectionString = ConfigurationManager.ConnectionStrings["myConnString"].ConnectionString;

    private void DeletingDataBase()
    {
        using (SqlConnection sqlConn = new SqlConnection(sqlConnectionString))
        {
            using (SqlCommand cmd = new SqlCommand())
            {
                string sqlQuery = "SELECT, INSERT, UPDATE, DELETE";
                cmd.Connection = sqlConn;
                cmd.CommandText = sqlQuery;
                try
                {
                    cmd.Connection.Open();
                    cmd.ExecuteNonQuery();
                }
                catch { }
                finally
                {
                    cmd.Connection.Close();
                }
            }
        }
    }