MongoDB低级查询

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@Test
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    public void testAnd(){
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        //agender='female' AND age > 27 
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        DBObject queryCondition = new BasicDBObject();
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        queryCondition.put("agender", "female");
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        queryCondition.put("age", new BasicDBObject("$gt", 27));
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        DBCursor dbCursor = coll.find(queryCondition);
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        assertEquals(1, dbCursor.size());
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        assertEquals("Jane", dbCursor.next().get("username"));
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    }

2 单个字段的OR操作


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@Test
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    public void testOrSingleField(){
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        DBObject queryCondition = new BasicDBObject();     
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        //age<15 OR age>27
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        queryCondition = new BasicDBObject();
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        BasicDBList values = new BasicDBList();
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        values.add(new BasicDBObject("age", new BasicDBObject("$gt", 27)));
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        values.add(new BasicDBObject("age", new BasicDBObject("$lt", 15)));
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        queryCondition.put("$or", values);
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        DBCursor dbCursor = coll.find(queryCondition);
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        assertEquals(3, dbCursor.size());
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        assertEquals("tom", dbCursor.next().get("username"));
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    }
3 多个字段的OR操作



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@Test
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    public void testOrMultiFields(){
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        DBObject queryCondition = new BasicDBObject();     
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        //agender=female OR age<=23
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        queryCondition = new BasicDBObject();
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        BasicDBList values = new BasicDBList();
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        values.add(new BasicDBObject("agender", "female"));
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        values.add(new BasicDBObject("age", new BasicDBObject("$lte", 23)));
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        queryCondition.put("$or", values);
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        DBCursor dbCursor = coll.find(queryCondition);
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        assertEquals(4, dbCursor.size());
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        assertEquals("Jim", dbCursor.next().get("username"));
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    }
4 IN操作 


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@Test
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    public void testIn(){
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        DBObject queryCondition = new BasicDBObject();     
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        //age in [13, 47]
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        queryCondition = new BasicDBObject();
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        BasicDBList values = new BasicDBList();
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        values.add(13);
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        values.add(47);
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        queryCondition.put("age", new BasicDBObject("$in", values));
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        DBCursor dbCursor = coll.find(queryCondition);
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        assertEquals(2, dbCursor.size());
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        assertEquals("tom", dbCursor.next().get("username"));
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    }
5 查询 name <> "li" and age >= 18的数据 


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BasicDBObject query = new BasicDBObject();
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query.put("name", new BasicDBObject().append("$ne", "liguohui"));
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query.put("age", new BasicDBObject().append("$gte", 18));
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coll.find(query)
6 查询 age> 10 and age<= 30的数据 


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BasicDBObject query = new BasicDBObject();
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query.put("age", new BasicDBObject().append("$gt", 10));
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query.put("age", new BasicDBObject().append("$lte", 30));
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coll.find(query);
7 查询 age in (20,22,24)的数据 


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BasicDBObject query = new BasicDBObject();
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BasicDBList values = new BasicDBList(); 
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values.add(20); 
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values.add(22);
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values.add(24);
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query.put("age", new BasicDBObject("$in", values)); 
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DBCursor cur = coll.find(query);
8 以年龄升序asc 


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DBCursor cur = coll.find().sort(new BasicDBObject().append("name", 1));
9 以年龄降序desc 

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DBCursor cur = coll.find().sort(new BasicDBObject().append("name", -1));
10 查询记录条数count() 


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BasicDBObject query = new BasicDBObject();
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query.put("age", new BasicDBObject("$lge", 10)); 
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long count = coll.getCount(query);
11

01
public boolean fileExistByUserId(String md5, Integer userId) {
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        boolean isExist = false;
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        try {
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            db = MongoDBConnection.getDB();
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            dbColleciton = db.getCollection("fileInfoCollection");
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            BasicDBObject query = new BasicDBObject();
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            query.put("fileMD5", md5);
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            query.put("userId", userId);
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            BasicDBList dbList = new BasicDBList();
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            dbList.add(0);
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            dbList.add(4);
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            dbList.add(FileInfoModelExtra.USERPRIVATE);
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            query.put("fileStatus", new BasicDBObject("$in", dbList)); 
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            DBCursor cursor = dbColleciton.find(query);        
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            if (cursor != null) {
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                // isExist = cursor.count() > 0 ? true : false;
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                isExist = cursor.iterator().hasNext() ? true : false;
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            }
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        } catch (MongoException e) {
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            logger.info(e);
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        } catch (RuntimeException e) {
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            logger.info(e.getMessage());
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        } catch (Exception e) {
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            logger.info(e.getMessage());
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        }
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        return isExist;
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    }