如何将条件放在mongodb中的数组项中

Question

我在mongo DB中有数据。但我是mongo的新手。有些人可以帮我从mongo获得正确的记录。

  {
    "_id" : ObjectId("5872edaf9704dc26c0cb770e"),
    "type" : "PUSH_NOTIFICATION",
    "alerts" : [ 
        {
            "_id" : ObjectId("5872edab9704dc26c0cb770c"),
            "alertId" : NumberLong(0),
            "userId" : NumberLong(1000100),
            "alertCode" : 3,
            "ticketId" : NumberLong(0),
        }
    ],
    "registrationId" : "010080fab2695a984fc16737b4637b40d4bbcfbfcfb87752851c99fd925e8427",
    "deleted" : false
}

上面是一排mongo表。我想获取ticketId不等于0的记录.taminId在Alert对象里面，这是一个警报数组。  我想用java编写查询。

Answer 1

你可以试试这个：

BasicDBObject Query = new BasicDBObject();
BasicDBObject fields = new BasicDBObject();
Query.put("alerts.ticketId",0);
fields.put("alerts.$", 1);

DBCursor cursor = collection.find(Query, fields);
while (cursor.hasNext()) {
    System.out.println(cursor.next());
}

希望这有帮助！

Answer 2

你可以这样做：

Query query = new Query();
query.addCriteria(Criteria.where("alerts.ticketId").not().is(0));

//OR

query.addCriteria(Criteria.where("alerts.ticketId").ne(0));

//OR using less than(lt) and greater than(gt) operator

query.addCriteria(Criteria.where("alerts.ticketId").lt(0).gt(0));