I have this code:

        private void FormProduction_FormClosed(object sender, FormClosedEventArgs e)
        {
            if (name != string.Empty && school != string.Empty)
            {
                if (id == -1) 
                {
                    MySqlConnection conn = new MySqlConnection(connStr);
                    MySqlCommand cmd = new MySqlCommand("INSERT Person(Name, School) VALUES (name, school)", conn);
                    conn.Open();
                    cmd.Parameters.AddWithValue("@name", name);
                    cmd.Parameters.AddWithValue("@school", school);
                    cmd.ExecuteNonQuery();
                    conn.Close();
                }
                else
                {
                    MySqlConnection conn = new MySqlConnection(connStr);
                    MySqlCommand cmd = new MySqlCommand("UPDATE Person SET Name=name, School=school WHERE Id=id", conn);
                    conn.Open();
                    cmd.Parameters.AddWithValue("@name", name);
                    cmd.Parameters.AddWithValue("@school", school);
                    cmd.Parameters.AddWithValue("@id", id);
                    cmd.ExecuteNonQuery();
                    conn.Close();
                }

                Administration.fill();
            }
        }

And my table Person doesn't change when I execute a program (any inserts and any updates). Where's an error?

CodePudding user response：

Hope this can help you:

More information on MySQL parametrized queries (official doc.)

private void FormProduction_FormClosed(object sender, FormClosedEventArgs e)
            {
                if (name != string.Empty && school != string.Empty)
                {
                    if (id == -1) 
                    {
                        MySqlConnection conn = new MySqlConnection(connStr);
                        MySqlCommand cmd = new MySqlCommand("INSERT Person(Name, School) VALUES (@name, @school)", conn);
                        conn.Open();
                        cmd.Parameters.AddWithValue("@name", name);
                        cmd.Parameters.AddWithValue("@school", school);
                        cmd.ExecuteNonQuery();
                        conn.Close();
                    }
                    else
                    {
                        MySqlConnection conn = new MySqlConnection(connStr);
                        MySqlCommand cmd = new MySqlCommand("UPDATE Person SET Name=@name, School=@school WHERE Id=@id", conn);
                        conn.Open();
                        cmd.Parameters.AddWithValue("@name", name);
                        cmd.Parameters.AddWithValue("@school", school);
                        cmd.Parameters.AddWithValue("@id", id);
                        cmd.ExecuteNonQuery();
                        conn.Close();
                    }
    
                    Administration.fill();
                }
            }