【转】Java操作MongoDB(2)

/**
 * <b>function:</b> 查询所有数据
 * @author hoojo
 * @createDate 2011-6-2 下午03:22:40
 */
private void queryAll() {
    print("查询users的所有数据：");
    //db游标
    DBCursor cur = users.find();
    while (cur.hasNext()) {
        print(cur.next());
    }
}
 
@Test
public void add() {
    //先查询所有数据
    queryAll();
    print("count: " + users.count());
    
    DBObject user = new BasicDBObject();
    user.put("name", "hoojo");
    user.put("age", 24);
    //users.save(user)保存，getN()获取影响行数
    //print(users.save(user).getN());
    
    //扩展字段，随意添加字段，不影响现有数据
    user.put("sex", "男");
    print(users.save(user).getN());
    
    //添加多条数据，传递Array对象
    print(users.insert(user, new BasicDBObject("name", "tom")).getN());
    
    //添加List集合
    List<DBObject> list = new ArrayList<DBObject>();
    list.add(user);
    DBObject user2 = new BasicDBObject("name", "lucy");
    user.put("age", 22);
    list.add(user2);
    //添加List集合
    print(users.insert(list).getN());
    
    //查询下数据，看看是否添加成功
    print("count: " + users.count());
    queryAll();
}

 4、 删除数据

@Test
public void remove() {
    queryAll();
    print("删除id = 4de73f7acd812d61b4626a77：" + users.remove(new BasicDBObject("_id", new ObjectId("4de73f7acd812d61b4626a77"))).getN());
    print("remove age >= 24: " + users.remove(new BasicDBObject("age", new BasicDBObject("$gte", 24))).getN());
}

 5、 修改数据

@Test
public void modify() {
    print("修改：" + users.update(new BasicDBObject("_id", new ObjectId("4dde25d06be7c53ffbd70906")), new BasicDBObject("age", 99)).getN());
    print("修改：" + users.update(
            new BasicDBObject("_id", new ObjectId("4dde2b06feb038463ff09042")), 
            new BasicDBObject("age", 121),
            true,//如果数据库不存在，是否添加
            false//多条修改
            ).getN());
    print("修改：" + users.update(
            new BasicDBObject("name", "haha"), 
            new BasicDBObject("name", "dingding"),
            true,//如果数据库不存在，是否添加
            true//false只修改第一天，true如果有多条就不修改
            ).getN());
    
    //当数据库不存在就不修改、不添加数据，当多条数据就不修改
    //print("修改多条：" + coll.updateMulti(new BasicDBObject("_id", new ObjectId("4dde23616be7c19df07db42c")), new BasicDBObject("name", "199")));
}

 6、 查询数据

@Test
public void query() {
    //查询所有
    //queryAll();
    
    //查询id = 4de73f7acd812d61b4626a77
    print("find id = 4de73f7acd812d61b4626a77: " + users.find(new BasicDBObject("_id", new ObjectId("4de73f7acd812d61b4626a77"))).toArray());
    
    //查询age = 24
    print("find age = 24: " + users.find(new BasicDBObject("age", 24)).toArray());
    
    //查询age >= 24
    print("find age >= 24: " + users.find(new BasicDBObject("age", new BasicDBObject("$gte", 24))).toArray());
    print("find age <= 24: " + users.find(new BasicDBObject("age", new BasicDBObject("$lte", 24))).toArray());
    
    print("查询age!=25：" + users.find(new BasicDBObject("age", new BasicDBObject("$ne", 25))).toArray());
    print("查询age in 25/26/27：" + users.find(new BasicDBObject("age", new BasicDBObject(QueryOperators.IN, new int[] { 25, 26, 27 }))).toArray());
    print("查询age not in 25/26/27：" + users.find(new BasicDBObject("age", new BasicDBObject(QueryOperators.NIN, new int[] { 25, 26, 27 }))).toArray());
    print("查询age exists 排序：" + users.find(new BasicDBObject("age", new BasicDBObject(QueryOperators.EXISTS, true))).toArray());
    
    print("只查询age属性：" + users.find(null, new BasicDBObject("age", true)).toArray());
    print("只查属性：" + users.find(null, new BasicDBObject("age", true), 0, 2).toArray());
    print("只查属性：" + users.find(null, new BasicDBObject("age", true), 0, 2, Bytes.QUERYOPTION_NOTIMEOUT).toArray());
    
    //只查询一条数据，多条去第一条
    print("findOne: " + users.findOne());
    print("findOne: " + users.findOne(new BasicDBObject("age", 26)));
    print("findOne: " + users.findOne(new BasicDBObject("age", 26), new BasicDBObject("name", true)));
    
    //查询修改、删除
    print("findAndRemove 查询age=25的数据，并且删除: " + users.findAndRemove(new BasicDBObject("age", 25)));
    
    //查询age=26的数据，并且修改name的值为Abc
    print("findAndModify: " + users.findAndModify(new BasicDBObject("age", 26), new BasicDBObject("name", "Abc")));
    print("findAndModify: " + users.findAndModify(
        new BasicDBObject("age", 28), //查询age=28的数据
        new BasicDBObject("name", true), //查询name属性
        new BasicDBObject("age", true), //按照age排序
        false, //是否删除，true表示删除
        new BasicDBObject("name", "Abc"), //修改的值，将name修改成Abc
        true, 
        true));
    
    queryAll();
}

 mongoDB不支持联合查询、子查询，这需要我们自己在程序中完成。将查询的结果集在Java查询中进行需要的过滤即可。

7、 其他操作