C# Adding rows in DataGridView

Question

I currently have the following codes and I would like to add a new row into the DataGridView when buttonX1 is clicked, how can i do this?

    private void Form1_Load(object sender, EventArgs e)
    {

        string query = "SELECT * FROM Bill";

        OleDbDataAdapter dAdapter = new OleDbDataAdapter(query, DBconn);

        OleDbCommandBuilder cBuilder = new OleDbCommandBuilder(dAdapter);

        DataTable dTable = new DataTable();

        dAdapter.Fill(dTable);

        //BindingSource to sync DataTable and DataGridView
        BindingSource bSource = new BindingSource();

        //set the BindingSource DataSource
        bSource.DataSource = dTable;

        //set the DataGridView DataSource
        dataGridViewX1.DataSource = bSource;

        dAdapter.Update(dTable);


    }

    private void buttonX1_Click(object sender, EventArgs e)
    {
        OleDbCommand cmd = new OleDbCommand();
        cmd.CommandType = CommandType.Text;
        cmd.CommandText = "INSERT INTO Bill (Item, Quantity, Price) VALUES ('Soft Drink', 1, 1)";
        cmd.Connection = DBconn;
        DBconn.Open();
        cmd.ExecuteNonQuery();
        DBconn.Close();
    }

Answer 1

      private void Select()
       {
              string query = "SELECT * FROM Bill";

                OleDbDataAdapter dAdapter = new OleDbDataAdapter(query, DBconn);

                OleDbCommandBuilder cBuilder = new OleDbCommandBuilder(dAdapter);

                DataTable dTable = new DataTable();

                dAdapter.Fill(dTable);

                //BindingSource to sync DataTable and DataGridView
                BindingSource bSource = new BindingSource();

                //set the BindingSource DataSource
                bSource.DataSource = dTable;

                //set the DataGridView DataSource
                dataGridViewX1.DataSource = bSource;

                dAdapter.Update(dTable);


            }

            private void buttonX1_Click(object sender, EventArgs e)
            {
                OleDbCommand cmd = new OleDbCommand();
                cmd.CommandType = CommandType.Text;
                cmd.CommandText = "INSERT INTO Bill (Item, Quantity, Price) VALUES ('Soft Drink', 1, 1)";
                cmd.Connection = DBconn;
                DBconn.Open();
                cmd.ExecuteNonQuery();
                DBconn.Close();

//call the Select function

                  Select();
            }

Answer 2

The way you pose you question suggests that you don't understand how it's supposed to work.

When you do the SqlDataAdapter.Fill, the DataTable is filled with a copy of the data from the database table. The DataGridView is an object that displays that data to the user.

When you want to add a row, you should add it in the DataTable dTable, but getting a new row:

(This goes in the Button click event).

DataRow dr = dTable.NewRow()

Putting your data in it:

dr[0] = something; dr[1] = somethng; etc.

Then add the row to the table

dTable.Rows.Add(dr) ;

When you have changed the data in the Table, you have to save the data back to the database using the DataSource.