I have following code running perfectly. It filter records based on single parameter.

public List<Orders> GetOrders(String email)
 {
     PersistenceManager pm = PMF.get().getPersistenceManager();
     Query query = pm.newQuery(Orders.class); 
     query.setFilter("Email == pEmail"); 
     query.setOrdering("Id desc"); 
     query.declareParameters("String pEmail");
     query.setRange(0,50);       
     return (List<Orders>) query.execute(email);
 }

Now i want to filter on multiple parameters. sdate and edate is Start Date and End Date. In datastore it is saved as Date (not String).

public List<Orders> GetOrders(String email,String icode,String sdate, String edate)
 {
     PersistenceManager pm = PMF.get().getPersistenceManager();
     Query query = pm.newQuery(Orders.class); 
     query.setFilter("Email == pEmail");
     query.setFilter("ItemCode == pItemCode");
     query.declareParameters("String pEmail");
     query.declareParameters("String pItemCode");
           .....//Set filter and declare other 2 parameters
           .....// 
           ......
     query.setRange(0,50);       
     query.setOrdering("Id desc");
     return (List<Orders>) query.execute(email,icode,sdate,edate);
 }

Any clue?