Question

开始学习mySQL，并坚持为什么这个命令不起作用。我在UPDATE命令和SELECT *函数之外取得了成功，所以我猜我在调用函数时犯了一个错误，或者％s需要不同...我的google foo没有找到任何东西所以我希望你们都可以帮助我！

非常感谢你寻找！

CODE：

def CheckBalance(UserName, BetAmount): #checks to make sure they can afford the bet.  Returns 0 for no 1 for yes
import mysql.connector

cnx = mysql.connector.connect(user='root', password='Password',
                      host='127.0.0.1',
                      database='crapsdatabase')
c = cnx.cursor()

BankRoll = c.execute("SELECT PlayerBank FROM player WHERE PlayerName = %s", UserName)

if(BankRoll < BetAmount) or (BetAmount < 0):
    c.close()
    return 0
if(BankRoll >= BetAmount):
    c.close()
    return 1

从我们的主程序中导入UpdateDatabase并将其命名为

from plugins.database.UpdateDatabase import UpdateBets

a = UpdateBets.CheckBalance("bob", 100)

print(a)

这会出现以下错误：

C:\python\python.exe C:/Users/Ray/Desktop/bot/plugins/CRAPS/CrapsUpdated.py
Traceback (most recent call last):
  File "C:/Users/Ray/Desktop/bot/plugins/CRAPS/CrapsUpdated.py", line 3, in <module>
    a = UpdateBets.CheckBalance("bob", 100)

  File "C:\Users\Ray\Desktop\bot\plugins\database\UpdateDatabase.py", line 16, in CheckBalance
    BankRoll = c.execute("SELECT PlayerBank FROM player WHERE PlayerName = %s", UserName)

  File "C:\python\lib\site-packages\mysql\connector\cursor.py", line 515, in execute
    self._handle_result(self._connection.cmd_query(stmt))
  File "C:\python\lib\site-packages\mysql\connector\connection.py", line 488, in cmd_query
    result = self._handle_result(self._send_cmd(ServerCmd.QUERY, query))

  File "C:\python\lib\site-packages\mysql\connector\connection.py", line 395, 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

Answer 1

你应该在带有撇号的查询中转义字符串文字，所以它应该是这样的：

c.execute("SELECT PlayerBank FROM player WHERE PlayerName = '%s'", UserName)

在函数

1 个答案: