Just don't repeat the same record please!

Question

Hi!

Please I am trying to don't allow repetition of records. But I cannot resolv it.
It says it's saved but he didnt (the same datas or anothers when I open my sql server table I didnt find the record that was saved as he said).

conn = new SqlConnection(connstr);

comm = new SqlCommand();

conn.Open();

SqlParameter data = new SqlParameter("@data", SqlDbType.NChar);

SqlParameter classe = new SqlParameter("@classe", SqlDbType.NChar);

comm.Parameters.Add(data);

comm.Parameters.Add(classe);

data.Value = DateTime.Today;

classe.Value = codigoBarraStocks.Text;

comm.Connection = conn;

comm.CommandText = "select count(*) from stocks where classe = @classe";

int count = (int)comm.ExecuteScalar();

if (count == 0)

try

{

comm.ExecuteNonQuery();

MessageBox.Show("Saved succefully");

}

catch (Exception)

{

MessageBox.Show("Not saved");

}

finally

{

conn.Close();

}

Vulpes · Answer

Well to add a record to the database you do of course need to use an INSERT statement rather than SELECT: comm.CommandText = insert into stocks (data classe) values (@data @classe); comm.ExecuteNonQuery(); So I assume you've done that somewhere else in your code and are now checking whether it's saved or not. To check whether it's saved you'll need: // blah comm.CommandText = select count(*) from stocks where classe = @classe; try { int count = (int)comm.ExecuteScalar(); if (count == 1) { MessageBox.Show(Saved successfully); } else if (count > 1) { MessageBox.Show(Saved but duplicated); } else { MessageBox.Show(Not saved); } } catch (Exception ex) { MessageBox.Show(ex.Message); } finally { conn.Close(); } Incidentally if the data column is an NChar rather than a DateTime in the database then depending on format you'll need something like: data.Value = DateTime.Today .ToString(yyyy/mm/dd) ; To ensure there's no duplication you'd be better making one of the columns into a primary key or giving it a unique constraint.