检查用户输入的用户名和密码在MYSQL数据库中是否存在

Question

Im new to python and I am creating a program that checks whether desired user entered username and password exists in database. Here is the code:

 import mysql.connector
 class data:
 def __init__(self):

    self.usernam = input("Enter user name: ")
    self.password= input("Enter Password: ")

 a=data()
 conn = mysql.connector.connect(host='localhost',user='root',passwd='root',database='user')


 loadname= ("select username from user where username='%s'")
 mycursor=conn.cursor()
 mycursor.execute(a.usernam, loadname)
 usercheck=mycursor.fetchone()
 loadpass= ("select pass from user where pass ='%s'")
 mycursor2=conncursor()
 mycursor2.execute(a.password,loadpass)
 passcheck=mycursor2.fetchone()


 if a.username == usercheck and a.password == passcheck:
     print ("pass")

 else:
     print ("sorry")
 conn.commit()
 conn.close()

Im getting the following errors:

   Traceback (most recent call last):
     File "C:\Users\HP\Desktop\2nd.py", line 16, in <module>
     mycursor.execute(a.usernam, loadname)
     File "C:\Python34\lib\site-packages\mysql\connector\cursor.py", line                                 507, in execute
     self._handle_result(self._connection.cmd_query(stmt))
     File "C:\Python34\lib\site-packages\mysql\connector\connection.py", line 722, in cmd_query
     result = self._handle_result(self._send_cmd(ServerCmd.QUERY, query))
     File "C:\Python34\lib\site-packages\mysql\connector\connection.py", line 640, in _handle_result
      raise errors.get_exception(packet)
     mysql.connector.errors.ProgrammingError: 1064 (42000): 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 'asaa' at line 1

Answer 1

mycursor.execute( loadname,a.username)

the query first then the args ...

I would strongly recommend you immediatly switch to an ORM like sqlalchemy

Answer 2

i don't know "mysql.connector" but if it work as MySQLdb, it should be something along the lines:

mycursor=conn.cursor()
mycursor.execute("select username from user where username=%s", a.username)