mongodb用子文档做为查询条件的两种方法

{
"_id": ObjectId("52fc6617e97feebe05000000"),
"age": 28,
"level": NumberInt(500),
"name": "name5",
"person": [
{
"level": 5,
"score": 100,
"ccc":{"ccc3":56,"fff3":78}
},
{
"level": 7,
"score": 90,
"like": "music"
}
],
"score": NumberInt(500),
"sex": "男"
}

db.testColl.find({"person.level":7});

db.testColl.find({"person.ccc.ccc3":56});

db.testColl.find({"person":{"$elemMatch":{"level":5}}});

db.testColl.find({"person":{"$elemMatch":{"ccc":{"$elemMatch":{"ccc3":56}}}}});

db.testColl.find({"person":{"$elemMatch":{"ccc":{"ccc3":56,"fff3":78}}}});

db.testColl.find({"person":{"$elemMatch":{"ccc.ccc3":56}}});