Python SQLite ToDo脚本

Question

I'm trying to make a script that asks the user to input a task, the task is then stored in a SQLite database. I am having a problem getting my delete function to work. Also when I input a new task I have to encapsulate in quotes in order to make it run.

import sqlite3
import sys 

con = sqlite3.connect('taskmgr.db')

def create_db():
    with con:
        c.execute("DROP TABLE IF EXISTS ToDo")
        c.execute("CREATE TABLE ToDo(Id int, Task char20, Due char20)") 

def select_task():
    with con:
        cursor = con.execute("SELECT Id, Task, Due from ToDo")
        for row in cursor:
            print "Id:" ,row[0]
            print "Task:" ,row[1]
            print "Due:" ,row[2]

def insert_task():
    with con:
        print("New Task\n")
        Id = input("Enter Id: ")
        Task = input("Enter Task: ")
        Due = input("Enter Due Date: ")
        c.execute("INSERT INTO ToDo VALUES(?, ?, ?)", (Id, Task, Due))
        con.commit()

def delete_record():
    with con:
        print("Enter task Id to delete:")
        user = int(input())
        c.execute("DELETE FROM ToDo WHERE Id=?",(user))

c = con.cursor()        
create_db()

target= int(8)
while target != 9:
    target=int(input("\nGood Morning Curtis!\n \nSelect option:\n 1.New Task\n 2.Select Task\n 3.Delete Task\n 9.Quit\n\nUser: "))

    if target ==1:
        insert_task()

    elif target ==2:
        select_task()

    elif target ==3:
        delete_record()

    elif target ==9:
        print("good bye")

Answer 1

Regarding the input requiring quotes, for Python 2 use raw_input() instead of input() .

The other problem is with the execute statement, specifically the values for the parameterised query needs to be of type tuple (or list), however, you are passing in an integer value. Try changing it to this:

c.execute("DELETE FROM ToDo WHERE Id=?",(user,))

The reason is that wrapping a single value in parentheses does not create a tuple:

>>> for user in 1, (1), (1,):
...     print user, type(user)
... 
1 <type 'int'>
1 <type 'int'>
(1,) <type 'tuple'>

From the above you can see that (1) is still 1 and is of type int. Wrapping it in () did not convert it to a tuple. However, (1,) is a tuple. Alternatively you could pass a list of the parameters, eg

c.execute("DELETE FROM ToDo WHERE Id=?",[user])