ERROR with SQL Server database connectivity

Question

Basically I am trying to develop a software and I am new in programming. I am trying to insert the data of textbox into SQL Server 2008 R2 Standard and I am getting an error:

System.NullReferenceException was unhandled

Here is my code.

SqlConnection con = new SqlConnection();
con.ConnectionString = "Data Source=(local);Initial Catalog=songs_db;Persist Security Info=True;User ID=sa;Password=iloveyourb";

con.Open();

DataSet ds = new DataSet();

String sql = "Select * From tbl_songdb";

SqlDataAdapter da = new SqlDataAdapter(sql, con);

DataRow drow = ds.Tables["tbl_songdb"].NewRow();  // I am getting error message here.
drow[1] = txt_songName.Text;
drow[2] = txt_minute.Text;
drow[3] = txt_albumnName.Text;
drow[4] = txt_location.Text;

ds.Tables["tbl_songdb"].Rows.Add(drow);
con.Close();

You don't have any code here that updates the database, just a `SELECT` statement. The `SqlDataAdapter` needs to be supplied with the SQL code to carry out `INSERT`s and `UPDATE`s. — Martin, Aug 21 '16 at 07:41
This question may have the answer to your question: http://stackoverflow.com/questions/1631054/using-sqldataadapter-to-insert-a-row — Martin, Aug 21 '16 at 07:43
i am using the codes written in the book and the same codes i can find on different sites which many developers are using but the same syntax are not working for me — Bhawesh Taunk, Aug 21 '16 at 07:50
Is it that ds isn't assigned any values before then tryng to assign drow from ds.Tables? — MikeT, Aug 21 '16 at 08:52

score 1 · Answer 1 · answered Aug 21 '16 at 10:56

1

actually my dataset was empty, thats why it was showing NULL error

 da.Fill(ds, "tbl_studentData");

i used these lines to fill it and now everything is working fine. thanks to all for giving their time.

answered Aug 21 '16 at 10:56

Bhawesh Taunk

11
3

Whencesoever · Answer 2 · 2016-08-21T09:23:29.930

0

Just do exactly what error said to you. Handle it with try catch like that:

      try{
    SqlConnection con = new SqlConnection();
            con.ConnectionString = "Data Source=(local);Initial Catalog=songs_db;Persist Security Info=True;User ID=sa;Password=iloveyourb";
            con.Open();
            DataSet ds = new DataSet();
            String sql = "Select * From tbl_songdb";
            SqlDataAdapter da = new SqlDataAdapter(sql, con);
            DataRow drow = ds.Tables["tbl_songdb"].NewRow();  // I am getting error message here.
            drow[1] = txt_songName.Text;
            drow[2] = txt_minute.Text;
            drow[3] = txt_albumnName.Text;
            drow[4] = txt_location.Text;
            ds.Tables["tbl_songdb"].Rows.Add(drow);
        da.Update(ds); 
    con.Close();
    }
    catch(Exception ex)
    {
MessageBox.Show(ex.ToString());

}

edited Aug 21 '16 at 09:23

answered Aug 21 '16 at 07:34

Whencesoever

2,218
15
26

its not showing error but the data from my textboxes is not being saved in database ??? what should i do?? – Bhawesh Taunk Aug 21 '16 at 07:39
use this: da.Update(ds); – Whencesoever Aug 21 '16 at 07:43
System.InvalidOperationException was unhandled – Bhawesh Taunk Aug 21 '16 at 08:09
try doing exactly as in my edited answer. Everything in try catch. – Whencesoever Aug 21 '16 at 08:20
But messagebox.show in catch block. It will show You the error if there is any. I eddited my answer with that message box. If there will be message box with error please write it here. – Whencesoever Aug 21 '16 at 09:24
i am happy to tell u that its done my DATASET was empty so i was getting NULL error i filled my dataset and then everything worked fine and many thanks to you for you help and ur time – Bhawesh Taunk Aug 21 '16 at 10:49
@BhaweshTaunk = ). – Whencesoever Aug 21 '16 at 11:04

score 0 · Answer 3 · answered Aug 21 '16 at 09:46

0

SqlConnection con = new SqlConnection();
con.ConnectionString = "Data Source=(local);Initial Catalog=songs_db;Persist Security Info=True;User ID=sa;Password=iloveyourb";

con.Open();

DataSet ds = new DataSet();

String sql = "Select * From tbl_songdb";

SqlDataAdapter da = new SqlDataAdapter(sql, con);
da.Fill(ds);
DataRow drow = ds.Tables[0].NewRow();  // I am getting error message here.
drow[1] = txt_songName.Text;
drow[2] = txt_minute.Text;
drow[3] = txt_albumnName.Text;
drow[4] = txt_location.Text;

ds.Tables[0].Rows.Add(drow);
SQLiteCommandBuilder cmdbuilder = new SQLiteCommandBuilder(da);
da.InsertCommand = cmdbuilder.GetInsertCommand();
da.Update(ds);
ds.AcceptChanges();
con.Close();

answered Aug 21 '16 at 09:46

Ali Muhammad Asif

1

Care to **explain** what you did? Don't just dump a pile of code on us and let us wonder what you might have done / changed / added !! .... – marc_s Aug 21 '16 at 09:48
sorry.... but its done and thank you very much for your time and next time i'll be more careful about this – Bhawesh Taunk Aug 21 '16 at 10:51
sorry its my mistake. I should explain it.... but its good to know that the problem is already solved. – Ali Muhammad Asif Aug 21 '16 at 21:27

ERROR with SQL Server database connectivity

3 Answers3