问如何解决JAVA程序中的SQL查询使用JDBC在尝试执行SELECT操作时抛出错误？

EN

int test=0;
System.out.println("Enter your Phone number:");
phone[i] = sc.nextInt();
    sc.nextLine();

System.out.println("Enter your name:");
name[i] = sc.nextLine();

System.out.println("Enter your address:");
address[i] = sc.nextLine();

System.out.println("Enter your Pick up city:");
city[i] = sc.nextLine();

System.out.println("Enter your Destination:");
destination[i] = sc.nextLine();

System.out.println("Enter your date of travel:");
date[i] = sc.nextLine();

Connection conn = null;
PreparedStatement stmt = null;


   Connection conx=null;
   try {
   String query1 = "SELECT * FROM `booking` WHERE fromcity="+city[i]+"AND tocity="+destination[i];
   conx = DriverManager.getConnection(DB_URL, USER, PASS);
   Statement st4 = conn.createStatement();
   ResultSet rst = st4.executeQuery(query1);

    //iterate through the java resultset
     while (rst.next()) 
     {
     test=test+1;

     }

         if(test==0)
            {
              System.out.println("no such flight route exists");
             }
                        st4.close();
     }//try closed here
                    catch(Exception e)
                    {
                        System.out.println("got an error");
                    }