python之数据库操作

时间：2023-03-09 13:17:26
python之数据库操作

数据库操作

Python 操作 Mysql 模块的安装

1
2
3
4
5
linux：
    yum install MySQL-python
window：
    http://files.cnblogs.com/files/wupeiqi/py-mysql-win.zip

SQL基本使用

1、数据库操作

1
2
3
show databases;
use [databasename];
create database  [name];

2、数据表操作

1
2
3
4
5
6
7
8
9
10
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 "-"
    ); 
 CREATE TABLE `wb_blog` (
     `id` smallint(8) unsigned NOT NULL,
     `catid` smallint(5) unsigned NOT NULL DEFAULT ',
     `title` varchar(80) NOT NULL DEFAULT '',
     `content` text NOT NULL,
     PRIMARY KEY (`id`),
     UNIQUE KEY `catename` (`catid`)
 ) ;

创建表wb_blog

3、数据操作

1
2
3
4
5
6
7
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

4、其他

1
2
3
主键
外键
左右连接

Python MySQL API

一、插入数据

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
import MySQLdb
  
conn = MySQLdb.connect(host='127.0.0.1',user='root',passwd='1234',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 
import MySQLdb

conn = MySQLdb.connect(host=',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

MySQLdb

注意：cur.lastrowid

二、删除数据

1
2
3
4
5
6
7
8
9
10
11
12
13
14
import MySQLdb
conn = MySQLdb.connect(host='127.0.0.1',user='root',passwd='1234',db='mydb')
cur = conn.cursor()
reCount = cur.execute('delete from UserInfo')
conn.commit()
cur.close()
conn.close()
print reCount

三、修改数据

1
2
3
4
5
6
7
8
9
10
11
12
13
import MySQLdb
conn = MySQLdb.connect(host='127.0.0.1',user='root',passwd='1234',db='mydb')
cur = conn.cursor()
reCount = cur.execute('update UserInfo set Name = %s',('alin',))
conn.commit()
cur.close()
conn.close()
print reCount

四、查数据

# ############################## fetchone/fetchmany(num)  ##############################

import MySQLdb

conn = MySQLdb.connect(host='127.0.0.1',user='root',passwd='1234',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='1234',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]
   

相关文章