C# :: Add / Save Data In Database

I had assign to do a project using c# window form.Now I am doing a smart part of coding which is let the data in textbox and using keypress function with a enter,the data will save in database and show on datagridview.I had searching how to do it online but all of them using mysql or sqlcommand something to do it! But my project is using the code that already done and can access without mysql or sql coding... Using this code to connect and show in datagridview...

using (TMPB_attn_DAL dalObj = new TMPB_attn_DAL())
{
dataGridView1.DataSource = dalObj.GetRecords().Cast<TMPB_attn>().ToList();
dataGridView1.Refresh();
}

This is the function code for me to add data inside database,it can run but just still cant save.

private void txt_proximity_KeyPress(object sender, KeyPressEventArgs e) {
if (e.KeyChar == (char)13) {
if (BusinessLogicLayer.TMS_GET_PROXIMITY_VALID_TO_USE(txt_proximity.Text) == true) {
TMPB_attn row_tmpb_attn = new TMPB_attn();

[code] ....