在C#中选择时出错

Question

我想使用以下代码显示来自Database的数据:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data.SqlClient;

namespace TestDatabase
{
    class Program
    {
        static void Main(string[] args)
        {
            string cs = @"Data Source=(LocalDB)\v11.0;
            AttachDbFilename=C:\Users\Mani\Desktop\DOT NET\Projects\
            TestDatabase\TestDatabase\Contact.mdf;
            Integrated Security=True";
            SqlConnection con = new SqlConnection(cs);
            string query = "select * from Stu";
            SqlCommand cmd = new SqlCommand(query, con);
            con.Open();
            SqlDataReader dr = cmd.ExecuteReader();
            while (dr.Read())
            {
                Console.WriteLine("Name: " + dr["Name"]);
            }
            con.Close();
        }
    }
}

当我运行我的代码时,发生以下异常.

{"An attempt to attach an auto-named database for file C:\\Users\\Mani\\Desktop\\DOT NET\\Projects\\\r\n  TestDatabase\\TestDatabase\\Contact.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share."}

请帮忙!

Answer 1

在字符串中间,文件路径中间有一个新行,它找不到该文件.将您的连接字符串全部放在一行,它应该解决问题.

所以:

string cs = @"Data Source=(LocalDB)\v11.0;AttachDbFilename=C:\Users\Mani\Desktop\DOT NET\Projects\TestDatabase\TestDatabase\Contact.mdf;Integrated Security=True";

要么

string cs = "Data Source=(LocalDB)\v11.0;"+
        "AttachDbFilename=C:\Users\Mani\Desktop\DOT NET\Projects\"+
        "TestDatabase\TestDatabase\Contact.mdf;"+
        "Integrated Security=True";