Python中操作mysql的pymysql模块详解

Python中操作mysql的pymysql模块详解

前言

pymsql是Python中操作MySQL的模块，pymysql支持python3.x。

一、安装

pip install pymysql

二、使用操作

1、执行SQL

#!/usr/bin/env pytho

# -*- coding:utf-8 -*-

importpymysql

# 创建连接

conn =pymysql.connect(host='127.0.0.1', port=3306, user='root', passwd='', db='tkq1', charset='utf8')

# 创建游标

cursor =conn.cursor()

# 执行SQL，并返回收影响行数

effect_row =cursor.execute("select * from tb7")

# 执行SQL，并返回受影响行数

#effect_row = cursor.execute("update tb7 set pass = '123' where nid = %s", (11,))

# 执行SQL，并返回受影响行数,执行多次

#effect_row = cursor.executemany("insert into tb7(user,pass,licnese)values(%s,%s,%s)", [("u1","u1pass","11111"),("u2","u2pass","22222")])

# 提交，不然无法保存新建或者修改的数据

conn.commit()

# 关闭游标

cursor.close()

# 关闭连接

conn.close()

注意：存在中文的时候，连接需要添加charset='utf8'，否则中文显示乱码。

2、获取查询数据

#! /usr/bin/env python

# -*- coding:utf-8 -*-

# __author__ = "TKQ"

importpymysql

conn =pymysql.connect(host='127.0.0.1', port=3306, user='root', passwd='', db='tkq1')

cursor =conn.cursor()

cursor.execute("select * from tb7")

# 获取剩余结果的第一行数据

row_1 =cursor.fetchone()

printrow_1

# 获取剩余结果前n行数据

# row_2 = cursor.fetchmany(3)

# 获取剩余结果所有数据

# row_3 = cursor.fetchall()

conn.commit()

cursor.close()

conn.close()

3、获取新创建数据自增ID

可以获取到最新自增的ID，也就是最后插入的一条数据ID

#! /usr/bin/env python

# -*- coding:utf-8 -*-

# __author__ = "TKQ"

importpymysql

conn =pymysql.connect(host='127.0.0.1', port=3306, user='root', passwd='', db='tkq1')

cursor =conn.cursor()

effect_row =cursor.executemany("insert into tb7(user,pass,licnese)values(%s,%s,%s)", [("u3","u3pass","11113"),("u4","u4pass","22224")])

conn.commit()

cursor.close()

conn.close()

#获取自增id

new_id =cursor.lastrowid

printnew_id

4、移动游标

操作都是靠游标，那对游标的控制也是必须的

注：在fetch数据时按照顺序进行，可以使用cursor.scroll(num,mode)来移动游标位置，如：

cursor.scroll(1,mode='relative') # 相对当前位置移动

cursor.scroll(2,mode='absolute') # 相对绝对位置移动

5、fetch数据类型

关于默认获取的数据是元祖类型，如果想要或者字典类型的数据，即：

#! /usr/bin/env python

# -*- coding:utf-8 -*-

# __author__ = "TKQ"

importpymysql

conn =pymysql.connect(host='127.0.0.1', port=3306, user='root', passwd='', db='tkq1')

#游标设置为字典类型

cursor =conn.cursor(cursor=pymysql.cursors.DictCursor)

cursor.execute("select * from tb7")

row_1 =cursor.fetchone()

printrow_1　　#{u'licnese': 213, u'user': '123', u'nid': 10, u'pass': '213'}

conn.commit()

cursor.close()

conn.close()

6、调用存储过程

a、调用无参存储过程

#! /usr/bin/env python

# -*- coding:utf-8 -*-

# __author__ = "TKQ"

importpymysql

conn =pymysql.connect(host='127.0.0.1', port=3306, user='root', passwd='', db='tkq1')

#游标设置为字典类型

cursor =conn.cursor(cursor=pymysql.cursors.DictCursor)

#无参数存储过程

cursor.callproc('p2') #等价于cursor.execute("call p2()")

row_1 =cursor.fetchone()

printrow_1

conn.commit()

cursor.close()

conn.close()

b、调用有参存储过程

#! /usr/bin/env python

# -*- coding:utf-8 -*-

# __author__ = "TKQ"

importpymysql

conn =pymysql.connect(host='127.0.0.1', port=3306, user='root', passwd='', db='tkq1')

cursor =conn.cursor(cursor=pymysql.cursors.DictCursor)

cursor.callproc('p1', args=(1, 22, 3, 4))

#获取执行完存储的参数,参数@开头

cursor.execute("select @p1,@_p1_1,@_p1_2,@_p1_3") #{u'@_p1_1': 22, u'@p1': None, u'@_p1_2': 103, u'@_p1_3': 24}

row_1 =cursor.fetchone()

printrow_1

conn.commit()

cursor.close()

conn.close()

三、关于pymysql防注入

1、字符串拼接查询，造成注入

正常查询语句：

#! /usr/bin/env python

# -*- coding:utf-8 -*-

# __author__ = "TKQ"

importpymysql

conn =pymysql.connect(host='127.0.0.1', port=3306, user='root', passwd='', db='tkq1')

cursor =conn.cursor()

user="u1"

passwd="u1pass"

#正常构造语句的情况

sql="select user,pass from tb7 where user='%s' and pass='%s'"%(user,passwd)

#sql=select user,pass from tb7 where user='u1' and pass='u1pass'

row_count=cursor.execute(sql) row_1 =cursor.fetchone()

printrow_count,row_1

conn.commit()

cursor.close()

conn.close()

构造注入语句：

#! /usr/bin/env python

# -*- coding:utf-8 -*-

# __author__ = "TKQ"

importpymysql

conn =pymysql.connect(host='127.0.0.1', port=3306, user='root', passwd='', db='tkq1')

cursor =conn.cursor()

user="u1' or '1'-- "

passwd="u1pass"

sql="select user,pass from tb7 where user='%s' and pass='%s'"%(user,passwd)

#拼接语句被构造成下面这样，永真条件，此时就注入成功了。因此要避免这种情况需使用pymysql提供的参数化查询。

#select user,pass from tb7 where user='u1' or '1'-- ' and pass='u1pass'

row_count=cursor.execute(sql)

row_1 =cursor.fetchone()

printrow_count,row_1

conn.commit()

cursor.close()

conn.close()

2、避免注入，使用pymysql提供的参数化语句

正常参数化查询

#! /usr/bin/env python

# -*- coding:utf-8 -*-

# __author__ = "TKQ"

importpymysql

conn =pymysql.connect(host='127.0.0.1', port=3306, user='root', passwd='', db='tkq1')

cursor =conn.cursor()

user="u1"

passwd="u1pass"

#执行参数化查询

row_count=cursor.execute("select user,pass from tb7 where user=%s and pass=%s",(user,passwd))

row_1 =cursor.fetchone()

printrow_count,row_1

conn.commit()

cursor.close()

conn.close()

构造注入，参数化查询注入失败。

#! /usr/bin/env python

# -*- coding:utf-8 -*-

# __author__ = "TKQ"

importpymysql

conn =pymysql.connect(host='127.0.0.1', port=3306, user='root', passwd='', db='tkq1')

cursor =conn.cursor()

user="u1' or '1'-- "

passwd="u1pass"

#执行参数化查询

row_count=cursor.execute("select user,pass from tb7 where user=%s and pass=%s",(user,passwd))

#内部执行参数化生成的SQL语句，对特殊字符进行了加\转义，避免注入语句生成。

# sql=cursor.mogrify("select user,pass from tb7 where user=%s and pass=%s",(user,passwd))

# print sql

#select user,pass from tb7 where user='u1\' or \'1\'-- ' and pass='u1pass'被转义的语句。

row_1 =cursor.fetchone()

printrow_count,row_1

conn.commit()

cursor.close()

conn.close()

结论：excute执行SQL语句的时候，必须使用参数化的方式，否则必然产生SQL注入漏洞。

3、使用存mysql储过程动态执行SQL防注入

使用MYSQL存储过程自动提供防注入，动态传入SQL到存储过程执行语句。

delimiter \\

DROP PROCEDURE IF EXISTS proc_sql \\

CREATE PROCEDURE proc_sql (

innid1 INT,

innid2 INT,

incallsql VARCHAR(255)

)

BEGIN

set@nid1 =nid1;

set@nid2 =nid2;

set@callsql =callsql;

PREPARE myprod FROM @callsql;

-- PREPARE prod FROM 'select * from tb2 where nid>? and nid<?'; 传入的值为字符串，？为占位符

-- 用@p1，和@p2填充占位符

EXECUTE myprod USING @nid1,@nid2;

DEALLOCATE prepare myprod;

END\\

delimiter ;

set@nid1=12;

set@nid2=15;

set@callsql ='select * from tb7 where nid>? and nid<?';

CALL proc_sql(@nid1,@nid2,@callsql)

pymsql中调用

#! /usr/bin/env python

# -*- coding:utf-8 -*-

# __author__ = "TKQ"

importpymysql

conn =pymysql.connect(host='127.0.0.1', port=3306, user='root', passwd='', db='tkq1')

cursor =conn.cursor()

mysql="select * from tb7 where nid>? and nid<?"

cursor.callproc('proc_sql', args=(11, 15, mysql))

rows =cursor.fetchall()

printrows #((12, 'u1', 'u1pass', 11111), (13, 'u2', 'u2pass', 22222), (14, 'u3', 'u3pass', 11113))

conn.commit()

cursor.close()

conn.close()

四、使用with简化连接过程

每次都连接关闭很麻烦，使用上下文管理，简化连接过程

#! /usr/bin/env python

# -*- coding:utf-8 -*-

# __author__ = "TKQ"

importpymysql

importcontextlib

#定义上下文管理器，连接后自动关闭连接

@contextlib.contextmanager

defmysql(host='127.0.0.1', port=3306, user='root', passwd='', db='tkq1',charset='utf8'):

conn =pymysql.connect(host=host, port=port, user=user, passwd=passwd, db=db, charset=charset)

cursor =conn.cursor(cursor=pymysql.cursors.DictCursor)

try:

yieldcursor

finally:

conn.commit()

cursor.close()

conn.close()

# 执行sql

with mysql() as cursor:

print(cursor)

row_count =cursor.execute("select * from tb7")

row_1 =cursor.fetchone()

printrow_count, row_1