嗨，所以我现在已经在这个项目上工作了大约一天（python和mySQL的新手） 所以我的问题是我如何查看文本框中的输入用户凭据是否已经是注册用户？
到目前为止，我已经设法将其连接到数据库并在数据库中存储了一些值，但是我似乎无法弄清楚如何扫描该数据库并在按下登录按钮时查看用户信息是否有效。
from tkinter import*
from tkinter import messagebox
import mysql.connector
import time
import datetime
import random
w = 300
h = 2
def register_user():
global username_info
global password_info
if len(username.get()) == 0 and len(password.get()) == 0:
print("Please fill in the Missing Info")
if len(username.get()) == 0 and len(password.get()) != 0 :
print("Please Enter a Username")
elif len(username.get()) != 0 and len(password.get()) == 0:
print("Please enter a Password")
else:
username_info = username.get()
password_info = password.get()
mydb = mysql.connector.connect(
host="localhost",
user="root",
passwd="root",
database="loginsystem"
)
mycursor = mydb.cursor()
sqlFormula = "INSERT INTO users (Username, Password) VALUES (%s, %s)"
insertvar = (username_info, password_info)
user1 = ("Joshua", "Cuyugan")
mycursor.execute(sqlFormula, insertvar)
mydb.commit()
username.set("")
password.set("")
def register():
global screen1
screen.withdraw()
screen1 = Toplevel(screen)
screen1.title("Registration")
screen1.geometry("500x250+700+350")
global username
global password
global username_entry
global password_entry
username = StringVar()
password = StringVar()
Label(screen1, text = " Please Enter Your Details Below", bg = "black", width = w , height = h, font = ("Calibri", 20) , fg = "white").pack()
Label(screen1, text = "").pack()
Label(screen1, text = "Username").place(x=220, y=85)
username_entry = Entry(screen1, textvariable = username, width="50").place(x=100, y=110)
Label(screen1, text = "Password").place(x=220, y=135)
password_entry = Entry(screen1, textvariable = password, width="50").place(x=100, y=160)
Button(screen1, text= "Register", height="1", width="20", command = register_user).place(x=80, y=200)
Button(screen1, text="Cancel", height="1", width="20", command= on_closereg).place(x=270, y=200)
screen1.protocol("WM_DELETE_WINDOW", on_closereg)
def login():
global screen2
mydb = mysql.connector.connect(
host="localhost",
user="root",
passwd="root",
database="loginsystem"
)
mycursor = mydb.cursor()
sql_select_Query = "select * from users"
mycursor.execute(sql_select_Query)
records = mycursor.fetchall()
for row in records:
print("Username" , row[1],)
print("Password", row[2], "\n" )
mycursor.close()
screen.withdraw()
screen2 = Toplevel(screen)
screen2.title("HOT or SUPER HOT")
screen2.geometry("800x600+550+220")
screen2.protocol("WM_DELETE_WINDOW", on_close)
def checker():
if len(username.get()) == 0 and len(password.get()) == 0:
print("Please fill in the Missing Info")
def on_close():
screen2.withdraw()
screen.update()
screen.deiconify()
screen.lift()
def on_closereg():
screen1.withdraw()
screen.update()
screen.deiconify()
screen.lift()
def verify():
global name
global userlogcred
global userpascred
userlogcred = username_verify.get()
userpascred = password_verify.get()
loadname = ("SELECT Username FROM users WHERE Username =%s")
loadpass = ("SELECT Password FFROM users WHERE Password =%s")
mydb = mysql.connector.connect(
host="localhost",
user="root",
passwd="root",
database="loginsystem"
)
mycursor = mydb.cursor()
if len(username_verify.get()) == 0 and len(password_verify.get()) == 0:
print("Please fill in the Missing Info")
if len(username_verify.get()) == 0 and len(password_verify.get()) != 0 :
print("Please Enter a Username")
elif len(username_verify.get()) != 0 and len(password_verify.get()) == 0:
print("Please enter a Password")
else:
mycursor.execute(loadname, userlogcred)
mycursor.execute(loadpass, userpascred)
logincheck = mycursor.fetchone()
loginpasscheck = mycursor.fetchone()
if logincheck is None:
print("Sorry, could not find you in the database\nOr it just isn't working")
if logincheck is not None and loginpasscheck is None:
print("Please Enter your Password")
elif logincheck is None and loginpasscheck is not None:
print("Please enter Your Username")
else:
print("pass\nSuccessfully loaded {} from the database".format(username_verify.get()))
def main_Screen():
global screen
screen = Tk()
screen.geometry("600x300+650+350")
screen.title("Login System")
Label(text = "Login System" , bg = "black", width = w , height = h, font = ("Calibri", 20) , fg = "white").pack()
Label(text = "").pack()
Button(text = "Login", height = h, width = "30", command = verify).place(x=50 , y=200)
Label(text = "").pack()
Button(text = "Register" ,height = h, width = "30", command = register).place(x=320 , y=200)
global username_verify
global password_verify
username_verify = StringVar()
password_verify = StringVar()
Label(screen, text = "Username").place(x=265, y = 90)
username_entry1 = Entry(screen, textvariable = username_verify, width = "80").place(x=57, y=110)
Label(screen, text="Password").place(x=267, y=140)
password_entry1 = Entry(screen, textvariable = password_verify, width = "80").place(x=57, y=160)
screen.mainloop()
main_Screen()
print("Hello World")
更新，我找到了此代码，我正尝试将其应用于我的项目，其中此代码将文本框内的输入值与数据库数据进行比较，并检查数据是否已经存在（如果存在），然后将其发送给您到另一种形式。
def verify():
global name
loadname = ("SELECT Username FROM users WHERE Username =%s")
loadpass = ("SELECT Password FFROM users WHERE Password = %s")
mydb = mysql.connector.connect(
host="localhost",
user="root",
passwd="root",
database="loginsystem"
)
mycursor = mydb.cursor()
if len(username_verify.get()) == 0 and len(password_verify.get()) == 0:
print("Please fill in the Missing Info")
if len(username_verify.get()) == 0 and len(password_verify.get()) != 0 :
print("Please Enter a Username")
elif len(username_verify.get()) != 0 and len(password_verify.get()) == 0:
print("Please enter a Password")
else:
mycursor.execute(loadname, username_verify.get())
mycursor.execute(loadpass, password_verify.get())
logincheck = mycursor.fetchone()
loginpasscheck = mycursor.fetchone()
if logincheck is None:
print("Sorry, could not find you in the database\nOr it just isn't working")
if logincheck is not None and loginpasscheck is None:
print("Please Enter your Password")
elif logincheck is None and loginpasscheck is not None:
print("Please enter Your Username")
else:
print("pass\nSuccessfully loaded {} from the database".format(login))
但是我遇到这个错误，请帮忙。
Traceback (most recent call last):
File "C:\Users\lenovo\AppData\Local\Programs\Python\Python37-32\lib\tkinter\__init__.py", line 1705, in __call__
return self.func(*args)
File "C:/Users/lenovo/PycharmProjects/Pylog/App.py", line 141, in verify
mycursor.execute(loadname, username_verify.get())
File "C:\Users\lenovo\PycharmProjects\Pylog\venv\lib\site-packages\mysql\connector\cursor.py", line 569, in execute
self._handle_result(self._connection.cmd_query(stmt))
File "C:\Users\lenovo\PycharmProjects\Pylog\venv\lib\site-packages\mysql\connector\connection.py", line 553, in cmd_query
result = self._handle_result(self._send_cmd(ServerCmd.QUERY, query))
File "C:\Users\lenovo\PycharmProjects\Pylog\venv\lib\site-packages\mysql\connector\connection.py", line 442, 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 '%s' at line 1
Hello World
更新后，我将username_verify.get()值放入变量中仍然不起作用，并且仍然发布了相同的错误。
答案 0 :(得分：1)
import mysql.connector as sql
class connections:
__HOST = 'localh`o`st'
__USERNAME = 'root'
__PASSWORD = ''
__DATABASE = 'testing'
def __init__(self):
self.con = sql.connect(host=connections.__HOST,user=connections.__USERNAME,password=connections.__PASSWORD,database=connections.__DATABASE)
def connect_database(self,username,password):
#append password and username in the emptey list below for later checkings
mypassword_queue =[]
sql_query = "SELECT *FROM users WHERE first_name ='%s' AND password ='%s'" % (username, password)
mycursor = self.con.cursor()
try:
mycursor.execute(sql_query)
myresults =mycursor.fetchall()
for row in myresults:
for x in row:
mypassword_queue.append(x)
except:
print('error occured')
if (username and password) in mypassword_queue:
print('there is something')
else:
print('there is no anything')
self.con.close()
root = connections()
#---you must have created a database with choice of your database name for this case it is testing
#---- the data inside has name as tumusiime and password 1234
root.connect_database('tumusiime','1234')
答案 1 :(得分：0)
我将为您提供一个适用于mysql.connector所有查询的代码
**config= {'user': your_user',
'password': 'your_pass',
'host': 'ip_of_your_db',
'database': 'name_of_your_db',
'raise_on_warnings': True}
def run_query(self,query):
try:
conn = mysql.connector.connect(**self._config)
if conn.is_connected():
print('run_query: Connecting MySql Db')
cur = conn.cursor()
cur.execute(query)
r= cur.fetchall()
return r
except mysql.connector.Error as err:
if err.errno == errorcode.ER_ACCESS_DENIED_ERROR:
print("run_query: Error in username or password")
elif err.errno == errorcode.ER_BAD_DB_ERROR:
print("run_query: Dabatase doesn't exist")
else:
print(err)
finally:
conn.commit()
conn.close()
每个查询都需要采用这种格式
query='SELECT * FROM {}'.format("your_db.your_table")
answer=self.run_query(query)