Python迁移MySQL数据到MongoDB脚本

　　MongoDB是一个文档数据库，在存储小文件方面存在天然优势。随着业务求的变化，需要将线上MySQL数据库中的行记录，导入到MongoDB中文档记录。

一、场景：线上MySQL数据库某表迁移到MongoDB，字段无变化。

二、Python模块：

使用Python的torndb,pymongo和time模块。

*注释：首先安装setup.py,pip,MySQLdb

执行如下命令即可：

pip install torndb

pip install pymongo

三、脚本内容如下：

[root ~]#cat nmytomongo.py

#!/usr/bin/env python
#fielName: mytomongo.py
#Author:xkops
#coding: utf-8
import torndb,pymongo,time
# connect to mysql database
mysql = torndb.Connection(host='127.0.0.1', database='database', user='username', password='password')
#connect to mongodb and obtain total lines in mysql
mongo = pymongo.MongoClient('mongodb://ip').database
mongo.authenticate('username',password='password')
countlines = mysql.query('SELECT max(table_field) FROM table_name')
count = countlines[0]['max(table_field)']

#count = 300
print count

i = 0 
j = 100
start_time = time.time()
#select from mysql to insert mongodb by 100 lines.
for i in range(0,count,100):
    #print a,b
    #print i
    #print 'SELECT * FROM quiz_submission where quiz_submission_id > %d and  quiz_submission_id <= %d' %(i,j)
    submission = mysql.query('SELECT * FROM table_name where table_field > %d and  table_field <= %d' %(i,j))
    #print submission 
    if submission:
        #collection_name like mysql table_name
        mongo.collection_name.insert_many(submission)
    else:
        i +=100
        j +=100
        continue
    i +=100
    j +=100
end_time = time.time()
deltatime = end_time - start_time
totalhour = int(deltatime / 3600)
totalminute = int((deltatime - totalhour * 3600) / 60)
totalsecond = int(deltatime - totalhour * 3600 - totalminute * 60)
#print migrate data total time consuming.
print "Data Migrate Finished,Total Time Consuming: %d Hour %d Minute %d Seconds" %(totalhour,totalminute,totalsecond)

*注释：按照自己的需求更改上述代码中的数据库地址，用户，密码，库名，表名以及字段名等。

四、执行迁移脚本:

[root ~]#python nmytomongo.py &> /tmp/migratelog.txt &

脚本执行完成后查看/tmp/migratelog.txt数据迁移消耗的时间。