python 3.5.2 "takes from 2 to 3 positional arguments but 4 were given"

Question

我正在用 python 编写一个程序，该程序连接到 mysql 数据库并可以访问和操作它。我正在使用 PyMySQL 来执行此操作，但是我对程序中不断出现的错误感到困惑。这是错误:

cursor.execute("SELECT * FROM Bookings WHERE ? = ?", record, recordtype)
TypeError: execute() takes from 2 to 3 positional arguments but 4 were given

但我在我的代码中没有看到任何错误(可能有点自信)。

def findbooking():
   recordtype =  input("Which field do you want to search?: ")
   record = input("Enter what you want to search: ")
   findbookingsql(record, recordtype)

def findbookingsql(record, recordtype):  #Connect to Database and find record specified
    conn = sql.connect(server,user, password,database)
    cursor = conn.cursor()
    cursor.execute("SELECT * FROM Bookings WHERE ? = ?",recordtype,record)
    row = cursor.fetchone()
    conn.close()
    return row

Answer 1

将参数封装在一个元组中，而不是独立的参数:

cursor.execute("SELECT * FROM Bookings WHERE ? = ?", (record, recordtype))