python连接MySQL、MongoDB、Redis、memcache等数据库的方法

#!/bin/env python
# -*- encoding: utf-8 -*-
#-------------------------------------------------------------------------------
# Purpose:     example for python_to_mongodb
# Author:      zhoujy
# Created:     2013-06-14
# update:      2013-06-14
#-------------------------------------------------------------------------------
import pymongo
import os

#建立和数据库系统的连接,创建Connection时，指定host及port参数
conn   = pymongo.Connection(host='127.0.0.1',port=27017)

#admin 数据库有帐号，连接-认证-切换库
db_auth = conn.admin
db_auth.authenticate('sa','sa')
#连接数据库
db = conn.abc

#连接表
collection = db.stu

#查看全部表名称
db.collection_names()
#print db.collection_names()

#访问表的数据，指定列
item = collection.find({},{"sname":1,"course":1,"_id":0})
for rows in item:
    print rows.values()

#访问表的一行数据
print collection.find_one()

#得到所有的列
for rows in collection.find_one():
    print rows

#插入
collection.insert({"sno":100,"sname":"jl","course":{"D":80,"S":85}})
#或
u = dict(sno=102,sname='zjjj',course={"D":80,"S":85})
collection.insert(u)

#得到行数
print collection.find().count()
print collection.find({"sno":100})

#排序，按照某一列的值。pymongo.DESCENDING:倒序；pymongo.ASCENDING:升序。按照sno倒序
item = collection.find().sort('sno',pymongo.DESCENDING)
for rows in item:
    print rows.values()

#多列排序
item = collection.find().sort([('sno',pymongo.DESCENDING),('A',pymongo.ASCENDING)])

#更新，第一个参数是条件，第二个参数是更新操作，$set,%inc,$push,$ne,$addToSet,$rename 等
collection.update({"sno":100},{"$set":{"sno":101}})
#更新多行和多列
collection.update({"sno":102},{"$set":{"sno":105,"sname":"SSSS"}},multi=True)

#删除，第一个参数是条件，第二个参数是删除操作。
collection.remove({"sno":101})

'''
sno:学号；sname：姓名；course：科目

db.stu.insert({"sno":1,"sname":"张三","course":{"A":95,"B":90,"C":65,"D":74,"E":100}})
db.stu.insert({"sno":2,"sname":"李四","course":{"A":90,"B":85,"X":75,"Y":64,"Z":95}})
db.stu.insert({"sno":3,"sname":"赵五","course":{"A":70,"B":56,"F":85,"G":84,"H":80}})
db.stu.insert({"sno":4,"sname":"zhoujy","course":{"A":64,"B":60,"C":95,"T":94,"Y":85}})
db.stu.insert({"sno":5,"sname":"abc","course":{"A":87,"B":70,"Z":56,"G":54,"H":75}})
db.stu.insert({"sno":6,"sname":"杨六","course":{"A":65,"U":80,"C":78,"R":75,"N":90}})
db.stu.insert({"sno":7,"sname":"陈二","course":{"A":95,"M":68,"N":84,"S":79,"K":89}})
db.stu.insert({"sno":8,"sname":"zhoujj","course":{"P":90,"B":77,"J":85,"K":68,"L":80}})
db.stu.insert({"sno":9,"sname":"ccc","course":{"Q":85,"B":86,"C":90,"V":87,"U":85}})

'''