public Person LoadPerson(int id)
{
try {
if (Ids.Contains(id)) {
con.Open();
string stm = "Select * from person where id = @theID";
SqlCommand cmd = new SqlCommand(stm, con);
cmd.Parameters.AddWithValue("@theId", id);
SqlDataReader reader = cmd.ExecuteReader();
reader.Read();
Person p = new Person();
p.Address = reader.GetString(2);
p.Id = reader.GetInt32(0);
p.Name = reader.GetString(1);
p.Rating = reader.GetInt32(3);
p.Ts = (byte[]) reader["ts"];
return p;
} else {
return null;
}
} finally {
con.Close();
}
}
private void SavePerson(object sender, RoutedEventArgs e)
{
Person p = new Person();
p.Ts = loadedPerson.Ts;
p.Address = AdressBox.Text;
p.Name = NameBox.Text;
p.Rating = Int32.Parse(RatingBox.Text);
p.Id = loadedPerson.Id;
service.SavePerson(p);
}
private void LoadPerson(object sender, RoutedEventArgs e)
{
loadedPerson = service.LoadPerson(Int32.Parse(IdBox.Text));
if (loadedPerson != null) {
NameBox.Text = loadedPerson.Name;
AdressBox.Text = loadedPerson.Address;
RatingBox.Text = "" + loadedPerson.Rating;
string b = "";
foreach (byte by in loadedPerson.Ts) {
b += by;
}
TsLabel.Content = b;
} else {
NameBox.Text = "Wrong ID!";
}
}
public void SavePerson(Person person)
{
try {
con.Open();
string stm1 = "Select * from person where id = @theID";
SqlCommand cmd1 = new SqlCommand(stm1, con);
cmd1.Parameters.AddWithValue("@theId", person.Id);
SqlTransaction transaction = con.BeginTransaction(IsolationLevel.Serializable);
cmd1.Transaction = transaction;
SqlDataReader reader = cmd1.ExecuteReader();
reader.Read();
Person p = new Person();
p.Address = reader.GetString(2);
p.Id = reader.GetInt32(0);
p.Name = reader.GetString(1);
p.Ts = (byte[])reader["ts"];
reader.Close();
if (Enumerable.SequenceEqual(p.Ts, person.Ts)) {
string stm2 =
"update person set name = @name, address = @address, rating = @rating where id = @id";
SqlCommand cmd2 = new SqlCommand(stm2, con);
cmd2.Parameters.AddWithValue("@name", person.Name);
cmd2.Parameters.AddWithValue("@address", person.Address);
cmd2.Parameters.AddWithValue("@rating", person.Rating);
cmd2.Parameters.AddWithValue("@ts", person.Ts);
cmd2.Parameters.AddWithValue("@id", person.Id);
cmd2.Transaction = transaction;
int i = cmd2.ExecuteNonQuery();
MessageBox.Show("" + i);
transaction.Commit();
} else {
transaction.Rollback();
MessageBox.Show("Different Timestamps, reread values are: " + p.ToString());
}
} finally {
con.Close();
}
}
