Question

我正在尝试在GAE上的ndb中创建1对多的关系。

当我尝试将客户端密钥分配给Customer.client_id属性时，将抛出此错误：

*** BadValueError：预期列表或元组，获得Key（'Client'，5629499534213120）

import sys, pprint  
pprint.pprint(sys.path)  
from flask import Flask  
from flask import Flask, render_template, request, session  

app = Flask(__name__)  
app.secret_key = 'superSecretKey'  
from google.appengine.ext import ndb  

class Client(ndb.Model):  
    email =  ndb.StringProperty()  
    name = ndb.StringProperty(indexed=True)  
    signup = ndb.DateTimeProperty(auto_now_add=True)  

 class Customer(ndb.Model):  
    client_id = ndb.KeyProperty(kind=Client, repeated=True)  
    email =  ndb.StringProperty()  
    name = ndb.StringProperty(indexed=True)  
    signup = ndb.DateTimeProperty(auto_now_add=True)  

 # this just creates a Client to use  
 if not ( Client.query( Client.name == "Bryan Wheelock").get()):  
 client = Client(  
   email = "bryan@email.com",  
   name = "Bryan Wheelock",  
 ).put()  

 @app.route('/')  
 def main_page():  
   client = Client.query( Client.name == "Bryan Wheelock").get()  
   session['client'] = client.key.urlsafe()  
   return render_template('index.html',  
       client=client  
   )  


 @app.route('/submitted', methods=['POST'])  
 def submitted_form():  
   client = ndb.Key(urlsafe=session['client']).get()  
   print "###########################################"  
   print("client.key = " + str(client.key))  
   customer = Customer()  
   customer.client_id = client.key  
   customer.name = request.form.get('id_name')  
   customer.put()  

   return render_template('submitted_form.html',  
       client=client,  
       customer=customer  
   )  



    @app.errorhandler(500)  
    def server_error(e):  
      # Log the error and stacktrace.  
        logging.exception('An error occurred during a request.')  
        return 'An internal error occurred.', 500  


        ERROR    2017-01-25 16:10:39,337 main.py:82] An error occurred during a request.
        Traceback (most recent call last):  
        File "/Users/bryanwheelock/work/flask_TDD/lib/flask/app.py", line 1988, in wsgi_app
          response = self.full_dispatch_request()  
        File "/Users/bryanwheelock/work/flask_TDD/lib/flask/app.py", line 1641, in full_dispatch_request
          rv = self.handle_user_exception(e)  
        File "/Users/bryanwheelock/work/flask_TDD/lib/flask/app.py", line 1544, in handle_user_exception
          reraise(exc_type, exc_value, tb)  
        File "/Users/bryanwheelock/work/flask_TDD/lib/flask/app.py", line 1639, in full_dispatch_request
          rv = self.dispatch_request()  
        File "/Users/bryanwheelock/work/flask_TDD/lib/flask/app.py", line 1625, in dispatch_request  
          return self.view_functions[rule.endpoint](**req.view_args)  
        File "/Users/bryanwheelock/work/flask_TDD/main.py", line 65, in submitted_form  
          customer.client_id = client.key  
        File "/Users/bryanwheelock/work/google-cloud-sdk/platform/google_appengine/google/appengine/ext/ndb/model.py", line 1400, in __set__
          self._set_value(entity, value)  
        File "/Users/bryanwheelock/work/google-cloud-sdk/platform/google_appengine/google/appengine/ext/ndb/model.py", line 1141, in _set_value
          (value,))  
    BadValueError: Expected list or tuple, got Key('Client', 5629499534213120)

Answer 1

在您的客户模型实体中

client_id = ndb.KeyProperty(kind=Client, repeated=True)

重复= True表示您将拥有一个Keys列表而不是一个键。所以你要么需要删除重复= True，要么需要像：

customer.client_id = [client.key]

或者它不是新实体

customer.client_id.append(client.key)

当我将键分配给ndb.KeyProperty时，为什么会出现BadValueError？

1 个答案: