how to stop duplicate value from text box to enter in datagridview which is connected to access db insert update and delete command?

Question

i am passing value from text box to datagridview which is also inserted in access db. but its also accepting duplicate values in datagridview. how do i prevent duplicates values ? here is picture project is in C# .Net framework.

here is Add button click event

private void AddButton_Click(object sender, EventArgs e) {

                    try
        {
            connection = new OleDbConnection("provider=microsoft.ace.oledb.12.0;data source=F:\\Floro_sense\\Floros.mdb");
            connection.Open();


            OleDbCommand command = new OleDbCommand("INSERT INTO Sflorotype(Sflorovalues, Sflorotypes) VALUES ('" + ValueTextBox.Text + "','" + TypeTextBox.Text + "');", connection);
            var result = command.ExecuteNonQuery();

            OleDbDataAdapter adapter = new OleDbDataAdapter("select * from Sflorotype", connection);
            DataTable table = new DataTable();
            adapter.Fill(table);

            var data = string.Join(Environment.NewLine,
            table.Rows.OfType<DataRow>().Select(x => string.Join(" ; ", x.ItemArray)));

            BindingSource bind = new BindingSource();
            bind.DataSource = table;
            dataGridViewList.DataSource = bind;
            adapter.Update(table);
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }
        finally
        {
            connection.Close();

        }

    }

Answer 1

You can write a method to check that a florotype already exists and use this method before inserting to the DB. If the FloroTypeExists() returns true then show a message box saying that the floro type already exists and do not add it to the DB.

(Pseudo-code)

private bool FloroTypeExists(string floroType)
{
  // Get your connection here
  string strSql = "select * from Sflorotype where Sflorotypes = '" + floroType + "'";
  OleDbDataAdapter adapter = new OleDbDataAdapter(strSql, connection);
  DataTable table = new DataTable();
  adapter.Fill(table);
  bool floroTypeExists = (table.Rows.Count > 0);
  return floroTypeExists;      
}

Some notes: You should refactor your code to write DB access code in dedicated classes and not in your Button click handler. Also you should not hard-code your DB conection strings and put them in config files.