05: MySQLdb 原生SQL语句操作数据库

1.1 MySQLdb安装与简介

　　1、MySQLdb 模块的安装（python3中目前这个模块还不可用）参考博客

　　　　1. linux：
　　　　　　　　yum install MySQL-python
　　　　2. window：
　　　　　　　　http://files.cnblogs.com/files/wupeiqi/py-mysql-win.zip

1.2 MySQLdb基本使用

　　1、原生SQL语句使用回顾

create table students
    (
        id int  not null auto_increment primary key,
        name char(8) not null,
        sex char(4) not null,
        age tinyint unsigned not null,
        tel char(13) null default "-"
    );

1、创建表

insert into students(name,sex,age,tel) values('alex','man',18,'')
 
delete from students where id =2;
 
update students set name = 'sb' where id =1;
 
select * from students

2、原生SQL语句基本操作

　　2、插入数据

import MySQLdb
 
conn = MySQLdb.connect(host='127.0.0.1',user='root',passwd='',db='mydb')
 
cur = conn.cursor()
 
reCount = cur.execute('insert into UserInfo(Name,Address) values(%s,%s)',('alex','usa'))
# reCount = cur.execute('insert into UserInfo(Name,Address) values(%(id)s, %(name)s)',{'id':12345,'name':'wupeiqi'})
 
conn.commit()
 
cur.close()
conn.close()
 
print reCount

1、插入单条数据

import MySQLdb
 
conn = MySQLdb.connect(host='127.0.0.1',user='root',passwd='',db='mydb')
 
cur = conn.cursor()
 
li =[
     ('alex','usa'),
     ('sb','usa'),
]
reCount = cur.executemany('insert into UserInfo(Name,Address) values(%s,%s)',li)
 
conn.commit()
cur.close()
conn.close()
 
print reCount

2、批量插入

　　3、删除数据

import MySQLdb
 
conn = MySQLdb.connect(host='127.0.0.1',user='root',passwd='',db='mydb')
 
cur = conn.cursor()
 
reCount = cur.execute('delete from UserInfo')
 
conn.commit()
 
cur.close()
conn.close()
 
print reCount

删除数据

　　4、修改数据

import MySQLdb
 
conn = MySQLdb.connect(host='127.0.0.1',user='root',passwd='',db='mydb')
 
cur = conn.cursor()
 
reCount = cur.execute('update UserInfo set Name = %s',('alin',))
 
conn.commit()
cur.close()
conn.close()
 
print reCount

修改数据

　　5、查询数据

# ############################## fetchone/fetchmany(num)  ##############################
 
import MySQLdb
 
conn = MySQLdb.connect(host='127.0.0.1',user='root',passwd='',db='mydb')
cur = conn.cursor()
 
reCount = cur.execute('select * from UserInfo')
 
print cur.fetchone()
print cur.fetchone()
cur.scroll(-1,mode='relative')
print cur.fetchone()
print cur.fetchone()
cur.scroll(0,mode='absolute')
print cur.fetchone()
print cur.fetchone()
 
cur.close()
conn.close()
 
print reCount
 
# ############################## fetchall  ##############################
 
import MySQLdb
 
conn = MySQLdb.connect(host='127.0.0.1',user='root',passwd='',db='mydb')
#cur = conn.cursor(cursorclass = MySQLdb.cursors.DictCursor)
cur = conn.cursor()
 
reCount = cur.execute('select Name,Address from UserInfo')
 
nRet = cur.fetchall()
 
cur.close()
conn.close()
 
print reCount
print nRet
for i in nRet:
    print i[0],i[1]

查询数据