前言
pymsql是Python中操作MySQL的模块,其使用方法和MySQLdb几乎相同。但目前pymysql支持python3.x而后者不支持3.x版本。
本文测试python版本:2.7.11。mysql版本:5.6.24
一、安装
pip3 install pymysql
二、使用操作
1、执行SQL
#!/usr/bin/env pytho # -*- coding:utf-8 -*- import pymysql # 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" import pymysql 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() print row_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" import pymysql 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 print new_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" import pymysql 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() print row_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" import pymysql 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() print row_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" import pymysql 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() print row_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" import pymysql 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() print row_count,row_1 conn.commit() cursor.close() conn.close()
构造注入语句:
#! /usr/bin/env python # -*- coding:utf-8 -*- # __author__ = "TKQ" import pymysql 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() print row_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" import pymysql 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() print row_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" import pymysql 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() print row_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 ( in nid1 INT, in nid2 INT, in callsql 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" import pymysql 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() print rows #((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" import pymysql import contextlib #定义上下文管理器,连接后自动关闭连接 @contextlib.contextmanager def mysql(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: yield cursor 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() print row_count, row_1
总结
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