MySqlConnection Conexao = new MySqlConnection("Persist Security Info = False; server = localhost;port = 3307; database=info3; uid = root; pwd = ");
            MySqlCommand comando = new MySqlCommand("SELECT CATEGORIA FROM HASHTAG", Conexao);
            comando.Parameters.AddWithValue("parametro", lb_categoria.Text);
            Conexao.Open();
            MySqlDataReader dados = comando.ExecuteReader();
            rtb_hashtag.Clear();
            while (dados.Read())
            {
                rtb_hashtag.AppendText(dados["Tags"].ToString();
            }