python操作mysql

Posted 2020-06-14

Python 操作 mysql 模块的安装

linux：

    yum install MySQL-python


　　安装  python-mysqldb

　　

tar zxf MySQL-python-1.2.3c1.tar.gz
cd MySQL-python-1.2.3c1
python setup.py install  

SQL常用操作：

1、数据库操作

show databases;
use [databasename];
create database  [name];

2、数据表操作

show tables;
 
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 "-"
    );

3、数据操作　　

insert into students(name,sex,age,tel) values(‘alex‘,‘man‘,18,‘151515151‘)
 
delete from students where id =2;
 
update students set name = ‘sb‘ where id =1;
 
select * from students

##############查询select######################

fetchall

import MySQLdb      #导入连接数据的模块
conn = MySQLdb.connect(host=‘10.10.50.30‘,user=‘root‘,passwd=‘boyojoy.com‘,db=‘yangmv‘)
#cur = conn.cursor(cursorclass = MySQLdb.cursors.DictCursor)    #以字典的格式返回结果,默认是元组
cur = conn.cursor()

reCount = cur.execute(‘select * from user‘) #execute得到执行命令结果的行数
data = cur.fetchall()                       #fetchall()获取数据库中所有数据

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

　　

fetchone,fetchmany

import MySQLdb
conn = MySQLdb.connect(host=‘127.0.0.1‘,user=‘root‘,passwd=‘1234‘,db=‘mydb‘)
cur = conn.cursor()
reCount = cur.execute(‘select * from user‘)

print cur.fetchone()    #执行一次，返回第一条数据
print cur.fetchone()    #每次二次，返回第二条数据
print cur.fetchmany(4)  #获取前4条数据

#指针定位
cur.scroll(0,mode=‘absolute‘)   #绝对位置，0坐标
cur.scroll(-1,mode=‘relative‘)  #相对位置，当前位置左移动1
print cur.fetchone()

cur.close()
conn.close()

　　

 

##############插入insert#######################

import MySQLdb
conn = MySQLdb.connect(host=‘10.10.50.30‘,user=‘root‘,passwd=‘boyojoy.com‘,db=‘yangmv‘)
cur = conn.cursor()

sql = "insert into user (name,address) value(%s,%s)"    #sql语句
params = (‘jay‘,‘taiwan‘)
reCount = cur.execute(sql,params)      #插入一条数据
conn.commit()                          #提交至mysql生效

#cur.lastrowid                         #获取插入数据的自增ID
cur.close()
conn.close()

print reCount   #查看成功执行了几条命令

　　

批量插入数据

import MySQLdb
conn = MySQLdb.connect(host=‘10.10.50.30‘,user=‘root‘,passwd=‘boyojoy.com‘,db=‘yangmv‘)
cur = conn.cursor()
li =[
     (‘alex‘,‘usa‘),
(‘sb‘,‘japan‘),
]
reCount = cur.executemany(‘insert into user(name,address) values(%s,%s)‘,li)
conn.commit()
cur.close()
conn.close()
print reCount

　　

 

 

##############删除delete#######################

import MySQLdb

conn = MySQLdb.connect(host=‘10.10.50.30‘,user=‘root‘,passwd=‘boyojoy.com‘,db=‘yangmv‘)
cur = conn.cursor()

sql = "delete from user where id = %s"    #sql语句
params = (1,)                           #删除id为1的数据
reCount = cur.execute(sql,params)      #删除一条数据
conn.commit()

cur.close()
conn.close()

print reCount

　　

 

##############更改update#######################

import MySQLdb

conn = MySQLdb.connect(host=‘10.10.50.30‘,user=‘root‘,passwd=‘boyojoy.com‘,db=‘yangmv‘)
cur = conn.cursor()

sql = "update user set name = %s where name = ‘wj‘" #把wj更改为yangmv
params = (‘yangmv‘,)
reCount = cur.execute(sql,params)      #修改数据
conn.commit()

cur.close()
conn.close()

print reCount