MongoDB的查询方法

代码：

db.blogs.insert([
{
“author”: “张三”,
“title”: “MongoDB简介”,
“content”: “它是介于关系型数据库和非关系型数据库之间的一种NoSQL数据库，用C++编写，是一款集敏捷性、可伸缩性、扩展性于一身的高性能的面向文档的通用数据库”,
“tags”: [
“MongoDB”,
“NoSQL”
],
“comment”: [
{
“name”: “Jack”,
“detail”: “Good！”,
“date”: ISODate(“2015-07-09 09:55:49”)
},
{
“name”: “Tom”,
“detail”: “Hello World！”,
“date”: ISODate(“2015-07-09 18:12:35”)
},
{
“name”: “Alice”,
“detail”: “你好，Mongo！”,
“date”: ISODate(“2015-07-10 20:30:30”)
}
],
“readCount”: 154
},
{
“author”: “李四”,
“title”: “1+1等于几”,
“content”: “有的人说1+1=2，因为这是老师从小告诉我们的；而有的人说1+1=11，这是两个1的组合；但是有些人就认为1+1=1，他们觉得1个团队加上另一个团队，会组成了一个更强大的团队！”,
“tags”: [
“story”,
“rule”,
“数学”
],
“comment”: [
{
“name”: “王小光”,
“detail”: “每个人心里边都有自己的答案。”,
“date”: ISODate(“2015-07-10 11:45:57”)
}
],
“readCount”: 367
},
{
“author”: “李四”,
“title”: “如何写一篇好的博客？”,
“content”: “1、目标；2、坚持；3、分享；4、学习；5、提高”,
“tags”: null,
“comment”: [
{
“name”: “小明”,
“detail”: “ComeOn!!!!”,
“date”: ISODate(“2015-07-10 14:49:06”)
},
{
“name”: “Nike”,
“detail”: “终身学习！”,
“date”: ISODate(“2015-07-11 10:22:36”)
},
{
“name”: “小红”,
“detail”: “贵在坚持吧、”,
“date”: ISODate(“2015-07-12 12:12:12”)
}
],
“readCount”: 1489,
“isTop”: true
}
])

Test Data