SQL COUNT(*)

         public int doCount(String No) throws SQLException {
             Class.forName(driver);
            connection conn = DriverManager.getConnection(url,username,password);           
            String sql = "SELECT COUNT(NO) FROM TABLE_NAME WHERE NO = ?;"
            PreparedStatement ps = conn.prepareStatement(sql);
            ps.setString(1, No);
            ResultSet rs = ps.executeQuery();
        
            while(rs.next()){
                result   =   rs.getInt(1);  
            }                   
        return result;
       }