OJB中的多条件查询

    项目还是一样，以一个reservation为例，一个reservation就是一个课程在实际中的体现，它有开始和终止时间还有状态等信息。timeslot就是定义了他的时间，里面有三个字段(timeslotID,start,end,reservationID)。

1。我要查询课程，输入的参数是一个时间段，得到的是一个reservation的列表。我可以这样做

1. /*
2.  *  (non-Javadoc)
3.  * @see org.pie.vls.Application.VLSBase#init()
4.  */
5. public void init() {
6.     try {
7.         broker = PersistenceBrokerFactory.defaultPersistenceBroker();
8.         broker.clearCache();
10.         //general criteria, with all the query condition
11.         Criteria crit = new Criteria();
12.         Criteria crit1 = null;
13.         List criteriaList = new Vector();
14.         //if the reservation id is not 0
15.         if (resvID > 0) {
16.             crit.addNotEqualTo("resvID", new Integer(this.resvID));
17.         }
19.         Iterator iter = this.reservationTimeslotList.iterator();
20.         while (iter.hasNext()) {
21.             //logger.debug ("TIMESLOT -----");
22.             ReservationTimeslot reservationTimeslot = (ReservationTimeslot) iter.next();
23.             /**
24.              * set the query condition list
25.              * start and end
26.              */
27.             startTimeUTC = reservationTimeslot.getStartDateTimeUTC();
28.             endTimeUTC = reservationTimeslot.getEndDateTimeUTC();
29.             if (this.selectType == Constants.BETWEEN_RESERVATIONS) {
30.                 crit1 = new Criteria();
31.                 //logger.debug ("BETWEEN " + startTimeUTC + " " + endTimeUTC);
32.                 crit1.addBetween("start", startTimeUTC, endTimeUTC);
33.                 Criteria critMore1 = new Criteria();
34.                 critMore1.addBetween("end", startTimeUTC, endTimeUTC);
35.                 Criteria critMore2 = new Criteria();
36.                 critMore2.addLessOrEqualThan("start", startTimeUTC);
37.                 critMore2.addGreaterOrEqualThan("end", endTimeUTC);
38.                 crit1.addOrCriteria(critMore1);
39.                 crit1.addOrCriteria(critMore2);
40.                 }
42.             criteriaList.add(crit1.copy(true, true, true));
43.         }
45.         if (criteriaList.size() > 0) {
46.             crit1 = new Criteria();
47.             for (int i = 0; i < criteriaList.size(); i++) {
48.                 crit1.addOrCriteria((Criteria) criteriaList.get(i));
49.             }
50.             crit.addAndCriteria(crit1);
51.         }
52.         logger.debug(crit);
53.         QueryByCriteria tquery = QueryFactory.newQuery(Timeslot.class, crit);
54.         this.timeslots = broker.getCollectionByQuery(tquery);
55.         broker.clearCache();
56.         broker.close();
57.     } catch (Throwable t) {
58.         logger.error(t.getMessage(), t);
59.     }
60. }

 

2. 如果我要创建一个reservation，要判断的是当前这个创建的reservation是否与其它的reservation有交叉点的时间，那查询条件就这样修改

1. broker = PersistenceBrokerFactory.defaultPersistenceBroker();
2. broker.clearCache();
3. //general criteria, with all the query condition
4. Criteria crit = new Criteria();
5. Criteria crit1 = null;
6. List criteriaList = new Vector();
7. if (this.selectType == Constants.TOUCHING_RESERVATIONS) {
8.     crit1 = new Criteria();
9.     /**
10. * <p>the start time is in between <code>this.startTimeUTC</code> and <code>this.endTimeUTC</code>
11.      */
12.     crit1.addGreaterOrEqualThan("start", startTimeUTC);
13.     crit1.addLessOrEqualThan("start", endTimeUTC);
14.     /**
15. * <p>the end time is in between <code>this.startTimeUTC</code> and <code>this.endTimeUTC</code>
16.      */
17.     Criteria crit2 = new Criteria();
18.     crit2.addGreaterOrEqualThan("end", startTimeUTC);
19.     crit2.addLessOrEqualThan("end", endTimeUTC);
21.     /**
22.      * <p>the start time is in less than <code>this.startTimeUTC</code> and 
23.      * the end time is greater than <code>this.endTimeUTC</code>
24.      */
25.     Criteria crit3 = new Criteria();
26.     crit3.addLessOrEqualThan("start", startTimeUTC);
27.     crit3.addGreaterOrEqualThan("end", endTimeUTC);
28.     crit1.addOrCriteria(crit2);
29.     crit1.addOrCriteria(crit3);
30. }
31. criteriaList.add(crit1.copy(true, true, true));
32. if (criteriaList.size() > 0) {
33.     crit1 = new Criteria();
34.     for (int i = 0; i < criteriaList.size(); i++) {
35.         crit1.addOrCriteria((Criteria) criteriaList.get(i));
36.     }
37.     crit.addAndCriteria(crit1);
38. }
39. QueryByCriteria tquery = QueryFactory.newQuery(Timeslot.class, crit);
40. this.timeslots = broker.getCollectionByQuery(tquery);
41. broker.clearCache();
42. broker.close();