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Strange behavior with flask and sqlalchemy

Strange behavior with flask and sqlalchemy

From:
Dominique Schramm
Date:
2012-10-11 @ 18:02
Hi there,

i am new to flask. Before flask I worked with bottle.

My problem is, I think so, the understanding how flask
works with sqlalchemy.

I created a small Flask app for using it as a restful api.
The inbound of sqlalchemy was made with this tutorial:

http://flask.pocoo.org/docs/patterns/sqlalchemy/#sql-abstraction-layer

I use only the abstraction layer, no orm and - I will still use
the abstraction layer and don't want to move to the orm.

If I start the application with python myapp.py and query the
route with the browser I got a result:

[{"faqentry_id": 1}, {"faqentry_id": 3}]

This result ist from the database and correct. But if I change
a value in the database, for example faq_entry = 3 -> 4 and
query the route via the browser again I got:

[{"faqentry_id": 1}, {"faqentry_id": 3}]

and not

[{"faqentry_id": 1}, {"faqentry_id": 4}]

The correct result will only appear, if I restart the application,
but this cannot be the right way, to restart always the application.

Can you help me?

Thanks and Cheers,

Dominique

Re: [flask] Strange behavior with flask and sqlalchemy

From:
Dominique Schramm
Date:
2012-10-11 @ 23:24
Hi there,

i found the answer: it was just an error with
sqlalchemy :( Now everything works perfectly.

Kind regards

> -----Original Message-----
> From: flask@librelist.com [mailto:flask@librelist.com] On Behalf Of
> Dominique Schramm
> Sent: Thursday, October 11, 2012 8:02 PM
> To: flask@librelist.com
> Subject: [flask] Strange behavior with flask and sqlalchemy
> 
> Hi there,
> 
> i am new to flask. Before flask I worked with bottle.
> 
> My problem is, I think so, the understanding how flask
> works with sqlalchemy.
> 
> I created a small Flask app for using it as a restful api.
> The inbound of sqlalchemy was made with this tutorial:
> 
> http://flask.pocoo.org/docs/patterns/sqlalchemy/#sql-abstraction-layer
> 
> I use only the abstraction layer, no orm and - I will still use
> the abstraction layer and don't want to move to the orm.
> 
> If I start the application with python myapp.py and query the
> route with the browser I got a result:
> 
> [{"faqentry_id": 1}, {"faqentry_id": 3}]
> 
> This result ist from the database and correct. But if I change
> a value in the database, for example faq_entry = 3 -> 4 and
> query the route via the browser again I got:
> 
> [{"faqentry_id": 1}, {"faqentry_id": 3}]
> 
> and not
> 
> [{"faqentry_id": 1}, {"faqentry_id": 4}]
> 
> The correct result will only appear, if I restart the application,
> but this cannot be the right way, to restart always the application.
> 
> Can you help me?
> 
> Thanks and Cheers,
> 
> Dominique

Re: [flask] Strange behavior with flask and sqlalchemy

From:
Steven Kryskalla
Date:
2012-10-12 @ 00:04
On Thu, Oct 11, 2012 at 4:24 PM, Dominique Schramm <info@schramm.by> wrote:
> Hi there,
>
> i found the answer: it was just an error with
> sqlalchemy :( Now everything works perfectly.
>

In case anyone has the same problem in the future, can you explain
what your fix was?

I think this same issue has been posted on the list before, e.g. here:


http://flask.pocoo.org/mailinglist/archive/2012/8/27/flask-sqlalchemy-caching-results/

-Steve

Re: [flask] Strange behavior with flask and sqlalchemy

From:
Dominique Schramm
Date:
2012-10-13 @ 06:22
Hi,

i am not sure whether my coding failure is the same as in the link
mentioned.

my fault was: instead of executing the query with the engine, I 
executed it with the database.

right: engine.execute
false: db.execute

Cheers

> -----Original Message-----
> From: flask@librelist.com [mailto:flask@librelist.com] On Behalf Of
> Steven Kryskalla
> Sent: Friday, October 12, 2012 2:04 AM
> To: flask@librelist.com
> Subject: Re: [flask] Strange behavior with flask and sqlalchemy
> 
> On Thu, Oct 11, 2012 at 4:24 PM, Dominique Schramm <info@schramm.by>
> wrote:
> > Hi there,
> >
> > i found the answer: it was just an error with
> > sqlalchemy :( Now everything works perfectly.
> >
> 
> In case anyone has the same problem in the future, can you explain
> what your fix was?
> 
> I think this same issue has been posted on the list before, e.g. here:
> 
> http://flask.pocoo.org/mailinglist/archive/2012/8/27/flask-sqlalchemy-
> caching-results/
> 
> -Steve