MySQL-python模块

1.  Python 操作 Mysql 模块的安装

linux:

pip install MySQL-python 或 yum -y install MySQL-python

windows: exe安装包

http://pan.baidu.com/s/1c2ugfvE

2. SQL基本使用

2.1 数据库操作

show databases;

use [databasename];

create database [databasename] charset utf8;

2.2 数据表操作

create database py CHARSET('utf8')
use py

create table students (
id int  not null auto_increment primary key,
name char(32) not null,
sex char(12) not null,
age tinyint unsigned not null,
tel char(13) null default "-",
nal char(64)
);

2.3 数据操作

insert into students(name,sex,age,tel,nal) values('alex','man',18,'','CN')

delete from students where id =2;

update students set name = 'sb' where id =1;

select * from students

2.4 其他

主键

外键

左右连接

3. Python MySQL API

3.1 插入数据

#!/use/bin/env python
# -*- coding:utf-8 -*-

import MySQLdb

conn = MySQLdb.connect('py', user='root', passwd='py123', db='py')
cur = conn.cursor()

info = [    ('go1','man',30,'13900000000', 'US'),    ('go2','man',28,'13900000001', 'HK'),]

info1 = ('mihui','man',30,'', 'US')
info2 = ['YeGangchan','man',28,'', 'HK']
#reCount = cur.execute('insert into students(name,sex,age,tel,nal) values(%s,%s,%s,%s,%s)', info1)
reCount = cur.execute('insert into students(name,sex,age,tel,nal) values(%s,%s,%s,%s,%s)', info2)
reCount2 = cur.execute('insert into students(name,sex,age,tel,nal) values(%s,%s,%s,%s,%s)', ('rain','female',18,'','NK'))
# 插入多条
reCount3 = cur.executemany('insert into students(name,sex,age,tel,nal) values(%s,%s,%s,%s,%s)', info)

conn.commit()
cur.close()
conn.close()
print(reCount)

注意：cur.lastrowid

3.2 删除数据

#!/use/bin/env python
# -*- coding:utf-8 -*-

import MySQLdb

conn = MySQLdb.connect(host='py', user='root', passwd='py123', db='py')
cur = conn.cursor()

reCount = cur.execute('delete from students where name=%s',('syl'))

conn.commit()
cur.close()
conn.close()

print(reCount)

3.3 修改数据

#!/use/bin/env python
# -*- coding:utf-8 -*-

import MySQLdb

conn = MySQLdb.connect(host='py', user='root', passwd='py123', db='py')

cur = conn.cursor()
reCount = cur.execute('update students set name=%s where name=%s',('Laonanhai', 'Oldboy'))
conn.commit()
cur.close()
conn.close()
print(reCount)

3.4 查询数据

#!/use/bin/env python
# -*- coding:utf-8 -*-

import MySQLdb

conn = MySQLdb.connect('py', user='root', passwd='py123', db='py')

cur = conn.cursor()

reCount = cur.execute('select * from students')
## fetchone()
print(cur.fetchone())
print(cur.fetchone())
print(cur.fetchone())
cur.scroll(-1, mode='relative')     #游标相对上移一个
print(cur.fetchone())
print(cur.fetchone())

print('##------')
cur.scroll(0, mode='absolute')      #游标移动到绝对位置0
# print(cur.fetchone())
# print(cur.fetchone())

print('##------ fetchmany()')
# print(cur.fetchmany())
print(cur.fetchmany(4))

cur.close()
conn.close()

print(reCount)

#!/use/bin/env python
# -*- coding:utf-8 -*-

import MySQLdb

conn = MySQLdb.connect(host='py', user='root', passwd='py123', db='py')
cur = conn.cursor()
#cur = conn.cursor(cursorclass=MySQLdb.cursors.DictCursor)

reCount = cur.execute('select * from students')

nRes = cur.fetchall()
cur.close()
conn.close()

print(reCount)
print(nRes)
for i in nRes:
    print(i[0],i[1])

3.5 事务回滚

students表创建语句：

CREATE TABLE `students` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` char(32) NOT NULL,
`sex` char(12) DEFAULT NULL,
`age` tinyint(3) unsigned NOT NULL,
`tel` char(13) DEFAULT '_',
`nal` char(64) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=7 DEFAULT CHARSET=utf8

如：select * from students现在的结果如下(id自增)

现在的最后一条数据的id为6

插入两条数据在commit()前行rollback()

#!/use/bin/env python
# -*- coding:utf-8 -*-

import MySQLdb

conn = MySQLdb.connect(host='py', user='root', passwd='py123', db='py')
cur = conn.cursor()

reCount = cur.execute('insert into students(name,sex,age,tel,nal) values(%s,%s,%s,%s,%s)', ('rain2','man',26,'','NK'))
reCount2 = cur.execute('insert into students(name,sex,age,tel,nal) values(%s,%s,%s,%s,%s)', ('rain3','female',22,'','NK'))

conn.rollback()
conn.commit()
cur.close()
conn.close()
print(reCount)
print(reCount2)

现在再来

select * from students现在的结果如下

最后一条数据的仍id为6

做一次真正数据插入：

#!/use/bin/env python
# -*- coding:utf-8 -*-

import MySQLdb

conn = MySQLdb.connect(host='py', user='root', passwd='py123', db='py')
cur = conn.cursor()

reCount = cur.execute('insert into students(name,sex,age,tel,nal) values(%s,%s,%s,%s,%s)', ('rain2','man',26,'','NK'))
reCount2 = cur.execute('insert into students(name,sex,age,tel,nal) values(%s,%s,%s,%s,%s)', ('rain3','female',22,'','NK'))

#conn.rollback()
conn.commit()
cur.close()
conn.close()
print(reCount)
print(reCount2)

select * from students现在的结果如下

结果id跳过了7,8

id AUTO_INCREMENT信息保存在内存中，rollback时不回滚AUTO_INCREMENT信息