Add or Update object from a form GAE python
I try to create a class which will add data from a form to a db.model, but my problem is that when I will try to add an existing book, I want to update the copies and not to add a new object. I really try to find an answer, I read books for programming in GAE, but I find nothing for my problem. Thank you in advance and I will really appreciate if someone answer with a sample code and not with just a command ( eg try get_by_id()).
Here is a part of my source
class Book(db.Model):
book_id = db.IntegerProperty()
title = db.StringProperty()
author = db.StringProperty()
copies = db.IntegerProperty()
isbn = db.IntegerProperty()
copyright_date = db.StringProperty()
category = db.StringProperty()
comments = db.StringProperty()
class Add(webapp.RequestHandler): #Form to input data
def get(self):
self.response.out.write("""
<html>
<body>
<form action="/sign" method="post">
<table border="0">
<tr>
<td>ISBN:</td> <td><input type="text" name="isbn"</td>
</tr>
<tr>
<td>Title:</td> <td><input type="text" name="title"</td>
</tr>
<tr>
<td>Author:</td> <td><input type="text" name="author"</td>
</tr>
<tr>
<td>Copies:</td> <td><input type="text" name="copies"</td>
</tr>
<tr>
<td>Copyright Date:</td> <td><input type="text" name="copyright_date"</td>
</tr>
<tr>
<td><div>Category:<开发者_JAVA技巧/td> <td><select>
<option name="category" value="adventure">Adventure</option>
<option name="category" value="comedy">Comedy</option>
<option name="category" value="dramatic">Dramatic</option>
<option name="category" value="mystery">Mystery</option>
<option name="category" value="science_fiction">Science Fiction</option></select></td>
</tr>
<tr><td>Comments:</td></tr></table>
<div><textarea name="comments" rows="5" cols="40" value="Add your comments here"></textarea></div>
<div><input type="submit" value="Add Book">
<input type="reset" value="Reset"></div>
</form>
</body>
</html>""")
class Guestbook(webapp.RequestHandler):
def post(self):
book = Book()
book.isbn = int(self.request.get('isbn'))
book.title = self.request.get('title')
book.author = self.request.get('author')
book.category = self.request.get('category')
book.copies = int(self.request.get('copies'))
book.copyright_date = self.request.get('copyright_date')
book.put()
class Stock(webapp.RequestHandler):
def get(self): #Retrieve all data from DataBase (Here is the StockHouse)
Book = db.GqlQuery("SELECT * FROM Book ")
for book in Book:
print book.book_id, book.isbn, book.title, book.author, book.category, book.copyright_date, book.copies, book.comments
in order to update an existing entry you'll need a different handler that will take the post arguments as well as the id or key of the entity to update. Usually this is in the url, e.g:
POST /updateentity/id
and then in the handler:
def get(self, id):
existing = Model.get_by_id(long(id))
model.field = self.request.get("field")
model.put()
You can use get_or_insert Model method. Also see this question.
加载中,请稍侯......
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