查看数据库

show databases;

创建数据库并允许中文插入

create database s12day9 charset utf8;

使用数据库

use s12day9;

查看表

show tables;

创建表

create table students

    (

        id int  not null auto_increment primary key,

        name char(32) not null,

        sex char(20) not null,

        age tinyint unsigned not null,

        tel char(13) null default "-"

    );

查看表结构

desc students; 

查看创建sql的语句（查看别人创建的sql语句,InnoDB 支持事物操作）

show create table students;  

插入数据

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

删除数据

delete from students where id =2;

修改数据

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

查询数据

select * from students 

查询年龄大于20学生的所有数据

select * from students where age> 20;

查询年龄大于20男生的所有数据

select * from students where age> 20 and sex='man';

查询年龄中含1学生的所有数据(模糊查询，%代表所有)

selsct * from students where age like "1%";

查询年龄中含1学生的姓名和性别（模糊查询，%代表所有）

select name,sex from students where age like "1%";

修改数据

update students set age =26 where name ='alex';

查询数据

select * from students 

批量修改

update students set age=26;

删除数据

delete from students where name='rain';

插入字段

alter table students add colum nal char(64)；

查看表结构

desc students;

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

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

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

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

# ##################### fetchone 取一条数据/fetchmany(num)  指定取几条数据#####################

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  取所有数据##############################

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]

import MySQLdb

conn = MySQLdb.connect(host='127.0.0.1',user='root',passwd='',db='mydb')

cur = conn.cursor()

reCount = cur.execute('insert into students(name,sex,age,tel,nal) values(%s,%s,%s,%s,%s)',('Jack','F',22,12342345,'name',"CN"))

reCount = cur.execute('insert into students(name,sex,age,tel,nal) values(%s,%s,%s,%s,%s)',('Rachel','F',26,35642345,'name',"CN"))

conn.rollback()

conn.commit()

cur.close()

conn.close()

print reCount