An attempt to attach an auto-named database for file failure

Question

when trying to log into the admin section of my asp.net website i get the following errors:

An attempt to attach an auto-named database for file C:\Users\joshy\Documents\Visual Studio 2015\WebSites\nas2\App_Data\nas.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share.

**it highlights the following lines of code in my connectionclass.cs

file:**

Line 113:        try
Line 114:        {
Line 115:            conn.Open();
Line 116:            int amountOfUsers = (int)command.ExecuteScalar();

here is the code for the users section of the connection class.cs file:

#region Users
    public static User LoginUser(string name, string password)
    {
        //Check if user exists
        string query = string.Format("SELECT COUNT(*) FROM nas.dbo.users WHERE name = '{0}'", name);
        command.CommandText = query;

        try
        {
            conn.Open();
            int amountOfUsers = (int)command.ExecuteScalar();

            if (amountOfUsers == 1)
            {
                //User exists, check if the passwords match
                query = string.Format("SELECT password FROM users WHERE name = '{0}'", name);
                command.CommandText = query;
                string dbPassword = command.ExecuteScalar().ToString();

                if (dbPassword == password)
                {
                    //Passwords match. Login and password data are known to us.
                    //Retrieve further user data from the database
                    query = string.Format("SELECT email, user_type FROM users WHERE name = '{0}'", name);
                    command.CommandText = query;

                    SqlDataReader reader = command.ExecuteReader();
                    User user = null;

                    while (reader.Read())
                    {
                        string email = reader.GetString(0);
                        string type = reader.GetString(1);

                        user = new User(name, password, email, type);
                    }
                    return user;
                }
                else
                {
                    //Passwords do not match
                    return null;
                }
            }
            else
            {
                //User does not exist
                return null;
            }
        }
        finally
        {

            conn.Close();
        }
    }

    public static string RegisterUser(User user)
    {
        //Check if user exists
        string query = string.Format("SELECT COUNT(*) FROM users WHERE name = '{0}'", user.Name);
        command.CommandText = query;

        try
        {
            conn.Open();
            int amountOfUsers = (int)command.ExecuteScalar();

            if (amountOfUsers < 1)
            {
                //User does not exist, create a new user
                query = string.Format("INSERT INTO users VALUES ('{0}', '{1}', '{2}', '{3}')", user.Name, user.Password,
                                      user.Email, user.Type);
                command.CommandText = query;
                command.ExecuteNonQuery();
                return "User registered!";
            }
            else
            {
                //User exists
                return "A user with this name already exists";
            }
        }
        finally
        {
            conn.Close();
        }
    }
    #endregion

More of the connectionclass.cs code:

using System.Collections;
using System.Configuration;
using System.Data.SqlClient;
using Entities;

public static class ConnectionClass
{
    private static SqlConnection conn;
    private static SqlCommand command;
    private static object toursdate;

    static ConnectionClass()
    {
        string connectionString = ConfigurationManager.ConnectionStrings["nas_connect"].ToString();
        conn = new SqlConnection(connectionString);
        command = new SqlCommand("", conn);

any help would be greatly appreciated.

Thank you.

Sarat Sarat · Accepted Answer · 2016-04-27T17:42:59

First of all please share entire code or please check you are trying to open a connection which is closed.

An attempt to attach an auto-named database for file failure

1 Answers