python防止sql注入的方法

python防止sql注入的方法:
1. 使用cursor.execute(sql, args)的参数位:

sql_str = "select * from py_msgcontrol.py_msgcontrol_file_base_info where file_name = %s"
args = ["12';select now();"]
conn = pymysql.connect(**conn_dic)
cursor = conn.cursor()
cursor.execute(sql_str, args)

　　cursor.execute函数将传入的args中的特殊符号进行了转义，从而防止了sql注入的问题。

　　注意点是要传入sql语句的字符串占位用引号包起来会出错，像这样:

sql_str = "select * from py_msgcontrol.py_msgcontrol_file_base_info where file_name = '%s'"

　　报错:

pymysql.err.ProgrammingError: (1064, "You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '12\';select now();''' at line 1")

2. 使用pymysql.escape_string对参数进行转义

args = pymysql.escape_string("12';select now();")
sql_str = "select * from py_msgcontrol.py_msgcontrol_file_base_info where file_name = '%s'" % args
conn = pymysql.connect(**conn_dic)
cursor = conn.cursor()
cursor.execute(sql_str)