я делаю вот так
public void insertNewCustomere(NewCustomer ncust) {
ContentValues values = new ContentValues();
values.put("cname", ncust.cName);
values.put("date", ncust.date);
values.put("caddress", ncust.cAddress);
mdb.insert(CREATE_NEWCUSTOMER, null, values);
if( mdb.insert(CREATE_NEWCUSTOMER, null, values)==-1)
{
Toast.makeText(this, "Name already exist", Toast.LENGTH_LONG)
.show();
ContentValues values1 = new ContentValues();
}
else
{
Toast.makeText(this, " \n Details Submited Successfully.Thank You", Toast.LENGTH_LONG)
.show();
ContentValues values2= new ContentValues();
}
}