Re: [SQLObject] Caching, and Nonexistant objects

On Sat, 2003-03-29 at 16:15, Luke Opperman wrote:
> Second, very bad things happen if I instantiate an object
> with an id that doesn't exist in the database (ie,
> Product(43) ). It is instantiated fine, but when an
> attribute is accessed it hangs python entirely. The cause of
> the hang is unclear at this point, and concerns me, but at a
> minimum we need a way to check if an object exists! Our
> feeling is that instantiating a non-existant ID should
> throw an exception immediately, but alternatively (or as the
> implementation of throwing an exception), a function to make
> sure the id is valid in the database should be created.
> Probably should be in the Connection classes, since all SQL
> should ideally be over there..
> 
> Now that I look through the code again, _SO_autoInit()
> should be taking care of this, but that only happens when
> attrs are accessed, and that's where the fatal hang is
> happening anyways.

The fatal hang is bad... it should just be an exception.

What do you get from connection.queryOne("SELECT bla FROM wherever WHERE
id = 43") ?  Or does it hang?  The queryOne method should just return
None, which'll cause some random exception (should be defined), but I
don't know why it would hang.

  Ian