mongodb学习笔记

# 安装：

# 使用：
# 无creat命令，use使用与创建数据库
> use mydb
switched to db mydb
> db
mydb> show dbs;
local   0.03125GB	# 数据库没数据，不显示内容

> book = {"title":"from beginner to master", "author":"qiwsir", "lang":"python"}
{
    "title" : "from beginner to master",
    "author" : "qiwsir",
    "lang" : "python"
}
> db.books.insert(book)
> db.books.find()
{ "_id" : ObjectId("554f0e3cf579bc0767db9edf"), "title" : "from beginner to master", "author" : "qiwsir", "lang" : "python" }

> show dbs
local   0.03125GB
mydb    0.0625GB

# 安装python操作库：
$ sudo pip install pymongo

>>> import pymongo
>>> pymongo.version
'3.0.1'
# 指定版本安装
$ sudo pip install pymongo==2.8

# 链接数据库：
>>> client = pymongo.MongoClient("localhost", 27017)

# 获取数据库mydb
>>> db = client.mydb
>>> db = client['mydb']	#作用相同

>>> db.collection_names()
[u'system.indexes', u'books']

# 获取这个集合books，并赋值给一个变量books
>>> books = db["books"]
>>> books = db.books	# 作用相同

# 编辑
>>> type(books)
<class 'pymongo.collection.Collection'>

# books对象包含的方法
>>> dir(books)
['_BaseObject__codec_options', '_BaseObject__read_preference', '_BaseObject__write_concern', '_Collection__create', '_Collection__create_index', '_Collection__database', '_Collection__find_and_modify', '_Collection__full_name', '_Collection__name', '__call__', '__class__', '__delattr__', '__dict__', '__doc__', '__eq__', '__format__', '__getattr__', '__getattribute__', '__getitem__', '__hash__', '__init__', '__iter__', '__module__', '__ne__', '__new__', '__next__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', '_command', '_count', '_delete', '_insert', '_socket_for_primary_reads', '_socket_for_reads', '_socket_for_writes', '_update', 'aggregate', 'bulk_write', 'codec_options', 'count', 'create_index', 'create_indexes', 'database', 'delete_many', 'delete_one', 'distinct', 'drop', 'drop_index', 'drop_indexes', 'ensure_index', 'find', 'find_and_modify', 'find_one', 'find_one_and_delete', 'find_one_and_replace', 'find_one_and_update', 'full_name', 'group', 'index_information', 'initialize_ordered_bulk_op', 'initialize_unordered_bulk_op', 'inline_map_reduce', 'insert', 'insert_many', 'insert_one', 'list_indexes', 'map_reduce', 'name', 'next', 'options', 'parallel_scan', 'read_preference', 'reindex', 'remove', 'rename', 'replace_one', 'save', 'update', 'update_many', 'update_one', 'with_options', 'write_concern']

''' 常用的一些方法 '''
>>> books.find_one()
{u'lang': u'python', u'_id': ObjectId('554f0e3cf579bc0767db9edf'), u'author': u'qiwsir', u'title': u'from beginner to master'}
# mongodb的shell指令
> db.books.findOne()
{
    "_id" : ObjectId("554f0e3cf579bc0767db9edf"),
    "title" : "from beginner to master",
    "author" : "qiwsir",
    "lang" : "python"
}

# 新增和查询
>>> b2 = {"title":"physics", "author":"Newton", "lang":"english"}
>>> books.insert(b2)
ObjectId('554f28f465db941152e6df8b')

>>> books.find().count()
2

>>> for i in books.find():
...     print i
... 
{u'lang': u'python', u'_id': ObjectId('554f0e3cf579bc0767db9edf'), u'author': u'qiwsir', u'title': u'from beginner to master'}
{u'lang': u'english', u'title': u'physics', u'_id': ObjectId('554f28f465db941152e6df8b'), u'author': u'Newton'}

# 批量插入
>>> n1 = {"title":"java", "name":"Bush"}
>>> n2 = {"title":"fortran", "name":"John Warner Backus"}
>>> n3 = {"title":"lisp", "name":"John McCarthy"}
>>> n = [n1, n2, n3]
>>> n
[{'name': 'Bush', 'title': 'java'}, {'name': 'John Warner Backus', 'title': 'fortran'}, {'name': 'John McCarthy', 'title': 'lisp'}]
>>> books.insert(n)
[ObjectId('554f30be65db941152e6df8d'), ObjectId('554f30be65db941152e6df8e'), ObjectId('554f30be65db941152e6df8f')]

>>> books.find().count()
6

# 条件查询
>>> books.find_one({"name":"Bush"})
{u'_id': ObjectId('554f30be65db941152e6df8d'), u'name': u'Bush', u'title': u'java'}

# 查询排序输出 关键字title pymongo.ASCENDING/pymongo.DESCEDING（升序/降序）
>>> for i in books.find().sort("title", pymongo.ASCENDING):
...     print i
... 
{u'_id': ObjectId('554f2b4565db941152e6df8c'), u'name': u'Hertz'}
{u'_id': ObjectId('554f30be65db941152e6df8e'), u'name': u'John Warner Backus', u'title': u'fortran'}
{u'lang': u'python', u'_id': ObjectId('554f0e3cf579bc0767db9edf'), u'author': u'qiwsir', u'title': u'from beginner to master'}
{u'_id': ObjectId('554f30be65db941152e6df8d'), u'name': u'Bush', u'title': u'java'}
{u'_id': ObjectId('554f30be65db941152e6df8f'), u'name': u'John McCarthy', u'title': u'lisp'}
{u'lang': u'english', u'title': u'physics', u'_id': ObjectId('554f28f465db941152e6df8b'), u'author': u'Newton'}

# 更新数据
# $set修改器，它可以用来指定键值，如果键不存在，就会创建。
>>> books.update({"name":"Hertz"}, {"$set": {"title":"new physics", "author":"Hertz"}})
{u'updatedExisting': True, u'connectionId': 4, u'ok': 1.0, u'err': None, u'n': 1}
>>> books.find_one({"author":"Hertz"})
{u'title': u'new physics', u'_id': ObjectId('554f2b4565db941152e6df8c'), u'name': u'Hertz', u'author': u'Hertz'}
'''
	修改器

	修改器	描述
	$set	用来指定一个键的值。如果不存在则创建它
	$unset	完全删除某个键
	$inc	增加已有键的值，不存在则创建（只能用于增加整数、长整数、双精度浮点数）
	$push	数组修改器只能操作值为数组，存在key在值末尾增加一个元素，不存在则创建一个数组
'''
	
# 删除
>>> books.remove({"name":"Bush"})
{u'connectionId': 4, u'ok': 1.0, u'err': None, u'n': 1}
>>> books.find_one({"name":"Bush"})

# 索引
>>> books.create_index([("title", pymongo.DESCENDING),])
u'title_-1'