FLASK-python ValueError：查看函数没有返回响应

Question

我想运行一个将数据插入到表中的sql函数。我下面的例子来说明here但每当我运行该脚本，我得到的错误“ValueError异常：查看功能并没有返回响应”

我的代码如下所示：

from flask import render_template, flash, redirect, request 
from app import app 
from .forms import LoginForm 
from .forms import RegistrationForm 
import sqlite3 as sql 

@app.route('/') 
@app.route('/index') 


@app.route('/registration', methods = ['GET','POST']) 
def registration(): 
    form = RegistrationForm() 

    if request.method == 'POST': 
     try: 
     card_id = request.form['card_id'] 
     pin = request.form['pin'] 
     account_id = request.form['account_id'] 


     with sql.connect("testDB.db") as con: 
      cur = con.cursor() 

      cur.execute("INSERT INTO atm_card (card_id,pin,account_id) VALUES (?,?,?,?)",(card_id,pin,account_id)) 

      con.commit() 
      msg = "Record successfully added" 
     except: 
     con.rollback() 
     msg = "error in insert operation" 

     finally: 
     return render_template("index.html",msg = msg) 
     con.close() 

我能有什么可能做错了吗？

Answer 1

如果请求方法是GET，会返回什么？您仅在POST请求上呈现模板。纠正它。

@app.route('/registration', methods = ['GET','POST']) 
def registration(): 
    form = RegistrationForm() 

    if request.method == 'POST': 
     try: 
     card_id = request.form['card_id'] 
     pin = request.form['pin'] 
     account_id = request.form['account_id'] 


     with sql.connect("testDB.db") as con: 
      cur = con.cursor() 

      cur.execute("INSERT INTO atm_card (card_id,pin,account_id) VALUES (?,?,?,?)",(card_id,pin,account_id)) 

      con.commit() 
      msg = "Record successfully added" 
     except: 
     con.rollback() 
     msg = "error in insert operation" 

     finally: 
     return render_template("index.html",msg = msg) 
     con.close() 
    else: 
     return render_template('index.html', form=form)