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POGoogle App Engine datastore model property returns none
 

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  1. POGoogle App Engine datastore model property returns none
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    <p>I am trying to create a basic use of the Google App Engine's datastore and db model. My model object is </p> <pre><code>class Table(db.Model): row = db.IntegerProperty() col = db.IntegerProperty() date = db.DateTimeProperty(auto_now_add=True) </code></pre> <p>it will be used to just hold a table of rows and columns. User gives input via html, and then I save the table and draw all of the tables in the datastore. I use <code>Table.all()</code> to get all tables from the datastore and then try to access their contents so that I can print the table but for some reason when table.row and table.col is read in <code>for y in range(row):</code> will apparently return a noneType, does anyone know why?</p> <pre><code>import webapp2 from google.appengine.ext.webapp.util import run_wsgi_app from google.appengine.ext import db from logging import error INITIAL_INPUT = """\ &lt;html&gt; &lt;body&gt; &lt;form action="/out?%s" method="POST"&gt; &lt;input type="text" name="row" /&gt; &lt;input type="text" name="col" /&gt; &lt;input type="submit" value="Submit" /&gt; &lt;/form&gt; &lt;/body&gt; &lt;/html&gt; """ class Table(db.Model): """Models an individual Guestbook entry with author, content, and date.""" row = db.IntegerProperty() col = db.IntegerProperty() date = db.DateTimeProperty(auto_now_add=True) class MainPage(webapp2.RequestHandler): def get(self): self.response.write(INITIAL_INPUT) class Out(webapp2.RequestHandler): def post(self): newRow = self.request.POST['row'] newCol = self.request.POST['col'] newTable = Table() newTable.row = int(newRow) if newRow else 1 newTable.col = int(newCol) if newCol else 1 newTable.put() tables = Table.all() for table in tables: self.drawTable(table.row, table.col) def drawTable(self, row , col): write = self.response.write write("&lt;html&gt;&lt;body&gt;&lt;table&gt;") for y in range(row): write("&lt;tr&gt;") for x in range(col): cell = "&lt;td bgcolor=\"#00FF00\"&gt;" + str(x) + " " + str(y) + "&lt;/td&gt;" if x % 2 == 0: cell = "&lt;td bgcolor=\"#FF0000\"&gt;" + str(x) + " " + str(y) + "&lt;/td&gt;" write(cell) write("&lt;/tr&gt;") write("&lt;/table&gt;&lt;/body&gt;&lt;/html&gt;") application = webapp2.WSGIApplication([ ('/', MainPage), ('/out', Out)] , debug=True) def main(*args, **kwds): run_wsgi_app(application) if __name__ == "__main__": main() </code></pre>
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    1. PO
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      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USDan McGrath
    1. USEasilyBaffled
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. COCheck the existing entities for Table. Sounds like you have at least one (maybe created previously) that doesn't have a value for `row`. You may want to set `required=True` on the row and col properties.
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      1. POGoogle App Engine datastore model property returns none
      1. USDaniel Roseman
    2. COHo do I do that is it just db.IntegerProperty(required=True)?
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      1. POGoogle App Engine datastore model property returns none
      1. USEasilyBaffled
    3. COYes that's right.
      singulars
      1. POGoogle App Engine datastore model property returns none
      1. USDaniel Roseman
 

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