"SELECT * FROM bill WHERE year=wyear AND account >= waccount1 AND account

I am new to work with mysql 5.7.21 and c # and vs2015. How to display the rows from the BILL table in DataSet. When I do not put a condition in the WHERE, it shows me a complete table, but I need only some rows.

myConnectionString = pwput;
MySqlConnectionconpara = new MySql.Data.MySqlClient.MySqlConnection();
conpara.ConnectionString = myConnec DataSetionString;
try
{
conpara.Open();
if (conpara.State == ConnectionState.Open)
{
string waccount1 = wwaccount1.ToString();
string waccount2 = wwaccount2.ToString();
string upita = "SELECT * FROM bill WHERE year=wyear AND account >= waccount1
AND account <= waccount2";
MySqlCommandcmdnal = new MySqlCommand(nupita, con);
cmdnal.Parameters.AddWithValue("@year", wyear);
MySqlDataAdapte radda = new MySqlDataAdapter(cmdnal);
MySqlCommandBuilder cbb = new MySqlCommandBuilder(adda);
DataSet dsd = new DataSet();
adda.Fill(dsd, "bill");
conpara.Close();

if (dsd != null)
{
dataGridView1.DataSource = dsd;
dataGridView1.DataMember = "bill";
Font = new System.Drawing.Font("Arial Unicode", 7);
dataGridView1.Font = Font;