如何使用存储在变量中的值从python mysql数据库获取特定行？

如何解决如何使用存储在变量中的值从python mysql数据库获取特定行？

我的代码在这里：

def draw_money():
    dr_list = [acc_num,acc_num_entry,with_btn,with_money,with_money_entry]

    for i in dr_list:
        i.destroy()

    new_acc = acc_num_var.get()
    money_amount = money.get()

    con = pymysql.connect(host="localhost",port=3306,user="root",password="",db="bankac")
    cur = con.cursor()
    query = "SELECT * FROM ac WHERE name = new_acc"
    cur.execute(query)`

但是当我执行此功能时，出现以下错误---

*Exception in Tkinter callback
Traceback (most recent call last):
  File "C:\Users\AMISHA SINGH\AppData\Local\Programs\Python\Python37-32\lib\tkinter\__init__.py",line 1705,in __call__    return self.func(*args)
  File "C:\Users\AMISHA SINGH\Documents\app\bank.py",line 33,in draw_money
    cur.execute(query)
  File "C:\Users\AMISHA SINGH\AppData\Local\Programs\Python\Python37-32\lib\site-packages\pymysql\cursors.py",line 170,in execute
    result = self._query(query)
  File "C:\Users\AMISHA SINGH\AppData\Local\Programs\Python\Python37-32\lib\site-packages\pymysql\cursors.py",line 328,in _query
    conn.query(q)
  File "C:\Users\AMISHA SINGH\AppData\Local\Programs\Python\Python37-32\lib\site-packages\pymysql\connections.py",line 517,in query
    self._affected_rows = self._read_query_result(unbuffered=unbuffered)
  File "C:\Users\AMISHA SINGH\AppData\Local\Programs\Python\Python37-32\lib\site-packages\pymysql\connections.py",line 732,in _read_query_result
    result.read()
  File "C:\Users\AMISHA SINGH\AppData\Local\Programs\Python\Python37-32\lib\site-packages\pymysql\connections.py",line 1075,in read
    first_packet = self.connection._read_packet()
  File "C:\Users\AMISHA SINGH\AppData\Local\Programs\Python\Python37-32\lib\site-packages\pymysql\connections.py",line 684,in _read_packet
    packet.check_error()
  File "C:\Users\AMISHA SINGH\AppData\Local\Programs\Python\Python37-32\lib\site-packages\pymysql\protocol.py",line 220,in check_error
    err.raise_mysql_exception(self._data)
  File "C:\Users\AMISHA SINGH\AppData\Local\Programs\Python\Python37-32\lib\site-packages\pymysql\err.py",line 109,in raise_mysql_exception
    raise errorclass(errno,errval)
pymysql.err.InternalError: (1054,"Unknown column 'new_acc' in 'where clause'")*

请帮助我。我已经尝试了很多方法，但是我无法弄清楚。我正在使用python模块tkinter和pymysql进行银行模拟。我想通过比较存储在python变量中的值来从数据库中获取特定行。

解决方法

您需要使用参数替换来传递变量，如下所示：

query = "SELECT * FROM ac WHERE name = %s"
cur.execute(query,(new_acc,))

请注意，传递给execute的值参数必须是in元组或列表，即使其中只有一个。 (new_acc,)是单个元素元组。

也可以使用略有不同的替换在字典中传递值：

query = "SELECT * FROM ac WHERE name = %(var_name)s"
cur.execute(query,{'var_name': new_acc})