接上篇，这里主要介绍利用Mongodb的cli对集合中的记录进行增删改查的操作，简单地说，就是Record级别上进行的操作。

从这里开始，我们用事先存在的(上)中提到的blogtest数据库做测试，其中有两个Collection，一个是book，另一个是user。

1 插入操作

1.1 向user集合中插入两条记录
> db.user.insert({'name':'Gal Gadot','gender':'female','age':28,'salary':11000})
> db.user.insert({'name':'Mikie Hara','gender':'female','age':26,'salary':7000})

1.2 同样也可以用save完成类似的插入操作
> db.user.save({'name':'Wentworth Earl Miller','gender':'male','age':41,'salary':33000})

2 查找操作

2.1 查找集合中的所有记录

> db.user.find()
{ "_id" : ObjectId("52442736d8947fb501000001"), "name" : "lfqy", "gender" : "male", "age" : 23, "salary" : 15 }
{ "_id" : ObjectId("52453cfb25e437dfea8fd4f4"), "name" : "Gal Gadot", "gender" : "female", "age" : 28, "salary" : 11000 }
{ "_id" : ObjectId("52453d8525e437dfea8fd4f5"), "name" : "Mikie Hara", "gender" : "female", "age" : 26, "salary" : 7000 }
{ "_id" : ObjectId("52453e2125e437dfea8fd4f6"), "name" : "Wentworth Earl Miller", "gender" : "male", "age" : 41, "salary" : 33000 }
{ "_id" : ObjectId("52454155d8947fb70d000000"), "name" : "not known", "sex_orientation" : "male", "age" : 13 }

(1)单一条件
a)Exact Equal:
查询age为了23的数据
> db.user.find({"age":23})
{ "_id" : ObjectId("52442736d8947fb501000001"), "name" : "lfqy", "gender" : "male", "age" : 23, "salary" : 15 }
b)Great Than:
查询salary大于5000的数据
> db.user.find({salary:{$gt:5000}})
{ "_id" : ObjectId("52453cfb25e437dfea8fd4f4"), "name" : "Gal Gadot", "gender" : "female", "age" : 28, "salary" : 11000 }
{ "_id" : ObjectId("52453d8525e437dfea8fd4f5"), "name" : "Mikie Hara", "gender" : "female", "age" : 26, "salary" : 7000 }
{ "_id" : ObjectId("52453e2125e437dfea8fd4f6"), "name" : "Wentworth Earl Miller", "gender" : "male", "age" : 41, "salary" : 33000 }
c)Fuzzy Match
查询name中包含'a'的数据
> db.user.find({name:/a/})
{ "_id" : ObjectId("52453cfb25e437dfea8fd4f4"), "name" : "Gal Gadot", "gender" : "female", "age" : 28, "salary" : 11000 }
{ "_id" : ObjectId("52453d8525e437dfea8fd4f5"), "name" : "Mikie Hara", "gender" : "female", "age" : 26, "salary" : 7000 }
{ "_id" : ObjectId("52453e2125e437dfea8fd4f6"), "name" : "Wentworth Earl Miller", "gender" : "male", "age" : 41, "salary" : 33000 }
查询name以G打头的数据
> db.user.find({name:/^G/})
{ "_id" : ObjectId("52453cfb25e437dfea8fd4f4"), "name" : "Gal Gadot", "gender" : "female", "age" : 28, "salary" : 11000 }

(2)多条件"与"
查询age小于30，salary大于6000的数据
> db.user.find({age:{$lt:30},salary:{$gt:6000}})
{ "_id" : ObjectId("52453cfb25e437dfea8fd4f4"), "name" : "Gal Gadot", "gender" : "female", "age" : 28, "salary" : 11000 }
{ "_id" : ObjectId("52453d8525e437dfea8fd4f5"), "name" : "Mikie Hara", &quo