sqlobject-discuss

[SQLObject] SQLObject / FireBird / WebWare

[Ian S. <ia...@et...>]

General questions :

How do SQLObject models fit into Webware?
Are there threading issues?
Does it work like dbPool?

If anyone has some simple (even pseudocode) examples that would be a great
help.

Thanks.

Re: [SQLObject] SQLObject / FireBird / WebWare

[Randall R. <ra...@ra...>]

On Thursday, September 25, 2003, at 05:49 PM, Ian Sparks wrote:

> General questions :
>
> How do SQLObject models fit into Webware?
> Are there threading issues?
> Does it work like dbPool?
>
> If anyone has some simple (even pseudocode) examples that would be a 
> great
> help.

Well, I haven't run into any big issues yet, and I've
been building my latest app (a combination articles site
and shopping cart) with it.  On the other hand, I'm not
trying to store my servlets in the db or anything.  I
also haven't needed transactions yet, but expect to.

The two easy ways of getting around the caching (when
updating articles, etc) are creating any needed objects
in awake() and destroying them in sleep(), or just
restarting the appserver on changes that would be
cached by a servlet.  I do the latter.

For me, SQLObject has replaced the pooling built into
psycopg.  Just in time, too, as psycopg 2.0 will not
have it anymore. :)

If you can be more specific about something you'd like
to see an example of, I can just pull out some of my
current code (assuming I'm doing whatever you want to
see).

-- 
Randall Randall <ra...@ra...>
"When you advocate any government action, you must first
believe that violence is the best answer to the question
at hand." -- Allen Thornton

[SQLObject] Re: SQLObject / FireBird / WebWare

[Ian S. <ian...@et...>]

"Randall Randall" <ra...@ra...> wrote in message
news:B6C...@ra......

> If you can be more specific about something you'd like
> to see an example of, I can just pull out some of my
> current code (assuming I'm doing whatever you want to
> see).

I'm guessing that something like :

#mypage.py:
from WebKit.Page import Page
import MySOClasses

class mypage(Page):
  ...
  def writeContent...
    test = MySoClasses.MyObject(1)
    test.name = 'Fred'

I'm assuming that if I have another servlet that has similar code that the
two servlets share :

1. A database connection.
2. The same SQLObject cache manager

Overall my assumption is that in MySOClasses.py I define a database
connection and the SQLObject classes I want to use and then I'm free to use
them in any servlet just by doing an "import MySOClasses" and that any
threading and cache management issues are handled for me?

Thanks.

Re: [SQLObject] Re: SQLObject / FireBird / WebWare

[Randall R. <ra...@ra...>]

On Monday, September 29, 2003, at 09:46 AM, Ian Sparks wrote:

> "Randall Randall" <ra...@ra...> wrote in message
> news:B6C...@ra......
> I'm guessing that something like :
>
> #mypage.py:
> from WebKit.Page import Page
> import MySOClasses

This is what I did, yes, though it was actually
from SiteSQL import *
since I have lots of SO objects in different files.

> class mypage(Page):
>   ...
>   def writeContent...
>     test = MySoClasses.MyObject(1)
>     test.name = 'Fred'
>
> I'm assuming that if I have another servlet that has similar code that 
> the
> two servlets share :
>
> 1. A database connection.
> 2. The same SQLObject cache manager
>
> Overall my assumption is that in MySOClasses.py I define a database
> connection and the SQLObject classes I want to use and then I'm free 
> to use
> them in any servlet just by doing an "import MySOClasses" and that any
> threading and cache management issues are handled for me?

That's been my assumption, and so far has been working. :)

If you expect to have issues with threading and flush caching,
then you'd want to use transactions, but currently I just restart
the appserver for major changes (it's not a financial site, just
articles and such).

I have a DBObject.py , which all my SQLObjects inherit from:
------------------------
from SQLObject import *

conn = PostgresConnection("user=myuser dbname=mydb password=mypass")
#trans = conn.transaction()

class DBObject(SQLObject):
   '''Base SQLObject for building database objects'''

   #_cacheValues = False
   _connection = conn
--------------------------
but which doesn't define any columns or anything, since those
wouldn't be inherited, per Ian's discussions on subclassing SO.
I *believe* that using transactions would be as simple as
an uncomment and beginning to use trans.commit() .  This might
not be the case.

It's also the case that I don't call any SOs in any __init__,
and don't leave them hanging around.  Some are called in awake,
and some in buildTemplate, etc (I use tplCompiler as well), so
it seems to me that I'm not getting any caching at all, due to
lack of reuse during development. However, I believe that having
all my SQLObjects inherit from DBObject, above, does give me
pooling during a request.

If I wrong, I hope someone corrects me as I spread disinformation. :)

-- 
Randall Randall <ra...@ra...>
"When you advocate any government action, you must first
believe that violence is the best answer to the question
at hand." -- Allen Thornton