How to insert datagridview data into SQL table

private void button23_Click(object sender, EventArgs e)
       {
      
 SqlCommand cmd = new SqlCommand();
                cmd.Connection = con;
                con.Open();

                for (int i = 0; i < dataGridView1.Rows.Count; i++)
                {
                    strquery = "insert into Febuary15 values (" + dataGridView1.Rows[i].Cells[0].Value + "," + dataGridView1.Rows[i].Cells[1].Value + "," + dataGridView1.Rows[i].Cells[2].Value + ", "+
                   " " + dataGridView1.Rows[i].Cells[3].Value + "," + dataGridView1.Rows[i].Cells[4].Value + "," + dataGridView1.Rows[i].Cells[5].Value + ", " +
                   " " + dataGridView1.Rows[i].Cells[6].Value + "," + dataGridView1.Rows[i].Cells[7].Value + "," + dataGridView1.Rows[i].Cells[8].Value + ", " +
                    " " + dataGridView1.Rows[i].Cells[9].Value + "," + dataGridView1.Rows[i].Cells[10].Value + "," + dataGridView1.Rows[i].Cells[11].Value + ", " +
                   " " + dataGridView1.Rows[i].Cells[12].Value + ", " + dataGridView1.Rows[i].Cells[13].Value + ", " + dataGridView1.Rows[i].Cells[14].Value + ", " +
                   " " + dataGridView1.Rows[i].Cells[15].Value + "," + dataGridView1.Rows[i].Cells[16].Value + "," + dataGridView1.Rows[i].Cells[17].Value + ", " +
                   " " + dataGridView1.Rows[i].Cells[18].Value + "," + dataGridView1.Rows[i].Cells[19].Value + "," + dataGridView1.Rows[i].Cells[20].Value + ", " +
                   " " + dataGridView1.Rows[i].Cells[21].Value + "," + dataGridView1.Rows[i].Cells[22].Value + "," + dataGridView1.Rows[i].Cells[23].Value + ", " +
                   " " + dataGridView1.Rows[i].Cells[24].Value + "," + dataGridView1.Rows[i].Cells[25].Value + "," + dataGridView1.Rows[i].Cells[26].Value + ", " +
                   " " + dataGridView1.Rows[i].Cells[27].Value + "," + dataGridView1.Rows[i].Cells[28].Value + "," + dataGridView1.Rows[i].Cells[29].Value + ", " +
                   " " + dataGridView1.Rows[i].Cells[30].Value + "," + dataGridView1.Rows[i].Cells[31].Value + "," + dataGridView1.Rows[i].Cells[32].Value + ", " +
                   " " + dataGridView1.Rows[i].Cells[33].Value + "," + dataGridView1.Rows[i].Cells[34].Value + "," + dataGridView1.Rows[i].Cells[35].Value + ", " +
                   " " + dataGridView1.Rows[i].Cells[36].Value + ")";
                    cmd.CommandText = strquery;
                    cmd.ExecuteNonQuery();
                    con.Close();

                }
                MessageBox.Show("Data Inserted Successfully");
            }