我无法使用Visual Studio将数据发送/插入到新数据库表中

Question

I am having trouble trying to send my data into my database.

Basically, I am using an ASP.Net Web form already implemented by Visual Studio 2012 (Professional). I have created an extra page called 'users.asps' with only three text boxes (username, full name and email). Then I also created a new database called 'Datatest.mdf' and added ONE table in the database called 'users' which includes three attributes: username (primary key), name and email.

Below is my code for the button on the page. Here is where I want to send all the inputted data into my database table.

protected void Button1_Click(object sender, EventArgs e)
{
    string strun = Request.Form["username"];
    string strna = Request.Form["name"];
    string strem = Request.Form["email"];

    OleDbConnection objconnection = null;
    OleDbCommand objcmd = null;
    string stringconnection = null;
    string strSQL = null;

    //connection string

    stringconnection = "provider=SQLOLEDB;data source=(LocalDb)\\v11.0;Initial Catalog=Datatest; Integrated Security=SSPI;";

    objconnection = new OleDbConnection(stringconnection);
    objconnection.ConnectionString = stringconnection;

    objconnection.Open();

    strSQL = "insert into users(username, name, email)values(?,?,?)";
    objcmd = new OleDbCommand(strSQL, objconnection);
    objcmd.Parameters.Add(new System.Data.OleDb.OleDbParameter("@username", strun));
    objcmd.Parameters.Add(new System.Data.OleDb.OleDbParameter("@name", strna));
    objcmd.Parameters.Add(new System.Data.OleDb.OleDbParameter("@email", strem));
    objcmd.ExecuteNonQuery();

    //close connection

    objconnection.Close();
    Response.Write("Entered Successfully");

}

When I run the form however I am getting an error "OleDbException was unhandled by user code" then says "SQL Server does not exist or access denied" that has an arrow pointing at objconnection.Open(); .

Despite where the error is located, I know the problem lies where my string connection is, I just don't know how I can fix it.

stringconnection = "provider=SQLOLEDB;data source=(LocalDb)\\v11.0;Initial Catalog=Datatest; Integrated Security=SSPI;";

Answer 1

For all your connectionstring propblems. You want to take a look in the sql department of that website.

Answer 2

I think that SQLOLEDB provider doesn't understand the connection string required to use a LocalDB.
(The LocalDB is more recent than SQLOLEDB)

Try to use SQLNCLI11 (The Sql Server Native Client v11)

"provider=SQLNCLI11;data source=(LocalDb)\\v11.0;
 Initial Catalog=Datatest; Integrated Security=SSPI;";

However, if you are in the initial stage of developping your application I really suggest to use the SqlClient classes like SqlConnection, SqlCommand etc and leave behind the OleDb and all its limitations. (Like no support for named parameters)

 using System.Data.SqlClient;
 ......


stringconnection = @"Data Source=(LocalDb)\\v11.0;Initial Catalog=Datatest;
                    Integrated Security=SSPI;";

using(objconnection = new SqlConnection(stringconnection))
{
    objconnection.Open();
    strSQL = "insert into users(username, name, email)values(@username, @name, @email)";
    using(objcmd = new SqlCommand(strSQL, objconnection))
    {
        objcmd.Parameters.Add(new SqlParameter("@username", strun));
        objcmd.Parameters.Add(new SqlParameter("@name", strna));
        objcmd.Parameters.Add(new SqlParameter("@email", strem));
        objcmd.ExecuteNonQuery();
    }
}
Response.Write("Entered Successfully");

Answer 3

Try to visit this link https://www.daniweb.com/software-development/csharp/threads/339949/how-to-establish-a-connection-with-sql-server-using-c

maybe it can help you on your database connection problem :)