摘要：

用Python写脚本也有一段时间了，经常操作数据库(MySQL)，现在就整理下对各类数据库的操作，如后面有新的参数会补进来，慢慢完善。

一，python 操作 MySQL:详情见：这里

mac 安装：http://sourceforge.net/projects/mysql-python/?source=dlp  再sudo python setup.py build

【apt-get install python-mysqldb】

【yum install python-devel  & pip install MySQL-python】

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

importMySQLdbimportos#建立和数据库系统的连接，格式#conn = MySQLdb.connect(host='localhost',user='root',passwd='123456',db='test',port=3306,charset='utf8')

#指定配置文件，确定目录,或则写绝对路径

cwd = os.path.realpath(os.path.dirname(__file__))

db_conf= os.path.join(cwd, 'db.conf')

conn= MySQLdb.connect(read_default_file=db_conf,host='localhost',db='test',port=3306,charset='utf8')#要执行的sql语句

query = 'select id from t1'

#获取操作游标

cursor =conn.cursor()#执行SQL

cursor.execute(query)#获取一条记录,每条记录做为一个元组返回,返回3，游标指到第2条记录。

result1 =cursor.fetchone()for i inresult1:printi#返回影响的行数

printcursor.rowcount#获取指定数量记录,每条记录做为一个元组返回,返回1，2，游标从第2条记录开始，游标指到第4条记录。

result2 = cursor.fetchmany(2)for i inresult2:for ii ini:printii#获取所有记录,每条记录做为一个元组返回,返回3，4，7，6,游标从第4条记录开始到最后。

result3 =cursor.fetchall()for i inresult3:for ii ini:printii#获取所有记录,每条记录做为一个元组返回,返回3，4，7，6,游标从第1条记录开始#重置游标位置，0为偏移量，mode＝absolute | relative,默认为relative

cursor.scroll(0,mode='absolute')

result3=cursor.fetchall()for i inresult3:for ii ini:printii#以下2种方法都可以把数据插入数据库：#(one)

for i in range (10,20):

query2= 'insert into t1 values("%d",now())' %i

cursor.execute(query2)#提交

conn.rollback()#(two)

rows =[]for i in range (10,20):

rows.append(i)

query2= 'insert into t1 values("%s",now())'

#executemany 2个参数,第2个参数是变量。

cursor.executemany(query2,rows)#提交

conn.commit()#选择数据库

query3 = 'select id from dba_hospital'

#重新选择数据库

conn.select_db('chushihua')

cursor.execute(query3)

result4=cursor.fetchall()for i inresult4:for ii ini:printii

#不定义query，直接执行：

cursor.execute("set session binlog_format='mixed'")#关闭游标，释放资源

cursor.close()'''+------+---------------------+

| id | modifyT |

+------+---------------------+

| 3 | 2010-01-01 00:00:00 |

| 1 | 2010-01-01 00:00:00 |

| 2 | 2010-01-01 00:00:00 |

| 3 | 2010-01-01 00:00:00 |

| 4 | 2013-06-04 17:04:54 |

| 7 | 2013-06-04 17:05:36 |

| 6 | 2013-06-04 17:05:17 |

+------+---------------------+'''

注意：在脚本中，密码写在脚本里面很容易暴露，这样可以用一个配置文件的方式来存密码，如db.conf：

[client]

user=root

password=123456

二，python 操作 MongoDB:详情见这里和这里以及这里

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

importpymongoimportos#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 initem:printrows.values()#访问表的一行数据

print collection.find_one()

#得到所有的列

for rows incollection.find_one():printrows#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

printcollection.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 initem:printrows.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}})'''

计算Mongodb文档中各集合的数目：

importpymongo

conn= pymongo.Connection(host='127.0.0.1',port=27017)

db= conn.abc #abc文档

for tb_name in db.collection_names(): #循环出各集合名

Count = db[tb_name].count() #计算各集合的数量

if Count > 2: #过滤条件

print tb_name + ':' +str(Count)'''conn = pymongo.Connection(host='127.0.0.1',port=27017)

db = conn.abc

for tb_name in db.collection_names():

print tb_name + ':'

exec('print ' + 'db.'+tb_name+'.count()') #变量当集合的处理方式

OR

conn = pymongo.Connection(host='127.0.0.1',port=27017)

db = conn.abc

for tb_name in db.collection_names():

mon_dic=db.command("collStats", tb_name) #以字典形式返回

print mon_dic.get('ns'),mon_dic.get('count')'''

updatetime:2015-06-30

MongoDB升级到了3.0之后，用python的连接会出错：

pymongo.errors.OperationFailure: command SON([('authenticate', 1), ('user', u'dba'), ('nonce', u'8c7842b068e14d3'), ('key', u'584ec63f1cdfd8525ce33d99cd269c2c')]) failed: auth failed

表示认证失败，说明MongoDB升级之后，对用用户的加密方式改变了。那就升级pymongo。

zhoujy@zhoujy:~$ sudo pip install pymongo --upgrade

[sudo] password forzhoujy:

...

...

Successfully installed pymongo

Cleaning up...

ubuntu10.10之后：

$ sudo apt-get install python-pip python-dev build-essential

$ sudo pip install--upgrade pip

$ sudo pip install --upgrade virtualenv

ubuntu10.10之前的老版本：

$ sudo apt-get install python-setuptools python-dev build-essential

$ sudo easy_install pip

$ sudo pip install--upgrade virtualenv

升级成功之后，继续执行python脚本，还是出错：

AttributeError: 'module' object has no attribute 'Connection'

表示没有 Connection ，pymongo升级完之后不支持了，看手册，发现用MongoClient 来替换了Connection。修改脚本：

conn = pymongo.Connection(host='127.0.0.1',port=27017)

改成

conn= pymongo.MongoClient(host='127.0.0.1',port=27017)

最后执行python，正常。

三，python 操作 Redis:详情见这里 和 这里/这里；集群连接

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

importredis

f= open('aa.txt')whileTrue:

line= f.readline().strip().split('#')if line == ['']:breakUserName,Pwd,Email=line#print name.strip(),pwd.strip(),email.strip()

rc = redis.StrictRedis(host='127.0.0.1',port=6379,db=15)

rc.hset('Name:' + UserName,'Email',Email)

rc.hset('Name:' + UserName,'Password',Pwd)

f.close()

alluser= rc.keys('*')#print alluser

print "===================================读出存进去的数据==================================="

for user inalluser:print '#'.join((user.split(':')[1],rc.hget(user,'Password'),rc.hget(user,'Email')))

一个pipeline的请看：

四，python 操作 memcache:详情见 这里 和 这里

importmemcache

mc = memcache.Client(['127.0.0.1:11211'],debug=1)

#!/usr/bin/env python#coding=utf-8

importMySQLdbimportmemcacheimportsysimporttimedefget_data(mysql_conn):#nn = raw_input("press string name:")

mc = memcache.Client(['127.0.0.1:11211'],debug=1)

t1=time.time()

value= mc.get('zhoujinyia')if value ==None:

t1=time.time()printt1

query= "select company,email,sex,address from uc_user_offline where realName = 'zhoujinyia'"cursor=mysql_conn.cursor()

cursor.execute(query)

item=cursor.fetchone()

t2=time.time()printt2

t= round(t2-t1)print "from mysql cost %s sec" %tprintitem

mc.set('zhoujinyia',item,60)else:

t2=time.time()

t=round(t2-t1)print "from memcache cost %s sec" %tprintvalueif __name__ =='__main__':

mysql_conn= MySQLdb.connect(host='127.0.0.1',user='root',passwd='123456',db='member',port=3306,charset='utf8')

get_data(mysql_conn)

上面介绍了一些python连接数据库，红色部分是连接操作的关键部分，大部分的操作没有列出来，具体的请见各官网。