sqlobject-discuss

[SQLObject] Substitute fieldID for fieldName

[Felix <fel...@te...>]

Hi everyone !!

I've a question (sorry if the email subject isn't to explicative) that i will
simplify in this example:

Three simple tables with relations:

class rank(SQLObject):
	id = IntCol()
	title = StringCol()
	persons = MultipleJoin('person')

class kind(SQLObject):
	id = IntCol()
	kindName = StringCol()
	persons = MultipleJoin('person')

class person(SQLObject):
	id = IntCol()
	name = StringCol()
	rankID = ForeignKey('rank')
	kindID = ForeignKey('kind')
	

What's the best way to get title and kindName instead rankID and kindID if i do person.get(1).select() (or else)?
With SQL queries i would do subslects or joins.

I think i could access through something like rank.persons or can i override _get_rankID() for getting rank title instead
rankID or add new fields in person class like:

class person(SQLObject):
	id = IntCol()
	name = StringCol()
	rankID = ForeignKey('rank')
	kindID = ForeignKey('kind')
	rankTitle = StringCol()
	kindName = StringCol()

	def _get_rankTitle(self):
		return rank.selectBy(id=self.rankID)

	def _get_kindName(self):
		return kind.selectBy(id=self.kindID)

Or maybe can i do this through sqlobject.sqlbuilder???

What's the best way ??? I think this is a common problem with documented solutions 

Thanks !

Re: [SQLObject] Substitute fieldID for fieldName

[Andrew B. <an...@ca...>]

On Mon, May 08, 2006 at 02:28:03PM +0200, Felix wrote:
> Hi everyone !!
> 
> I've a question (sorry if the email subject isn't to explicative) that i will
> simplify in this example:
> 
> Three simple tables with relations:
> 
> class rank(SQLObject):

Python code almost always has Capitalised class names (See also
http://www.python.org/dev/peps/pep-0008/), i.e. "class Rank(SQLObject):".  This
will help make something else clearer:

> 	id = IntCol()
> 	title = StringCol()
> 	persons = MultipleJoin('person')
> 
> class kind(SQLObject):
> 	id = IntCol()
> 	kindName = StringCol()
> 	persons = MultipleJoin('person')
> 
> class person(SQLObject):
> 	id = IntCol()
> 	name = StringCol()
> 	rankID = ForeignKey('rank')
> 	kindID = ForeignKey('kind')

Make these last two lines be just:

    rank = ForeignKey()
    kind = ForeignKey()

(and if you name the classes "Rank" and "Kind", then there's no possible
confusion to worry about here).

> 
> What's the best way to get title and kindName instead rankID and kindID if i do person.get(1).select() (or else)?
> With SQL queries i would do subslects or joins.

    Person.get(1).rank.title
    Person.get(1).kind.kindName

> I think i could access through something like rank.persons or can i override _get_rankID() for getting rank title instead
> rankID or add new fields in person class like:

Right, you can make properties to be shortcuts to the above code snippets.

-Andrew.

Re: [SQLObject] Substitute fieldID for fieldName

[Oleg B. <ph...@ma...>]

On Mon, May 08, 2006 at 02:28:03PM +0200, Felix wrote:
> Three simple tables with relations:
> 
> class rank(SQLObject):
> 	id = IntCol()
> 	title = StringCol()
> 	persons = MultipleJoin('person')
> 
> class kind(SQLObject):
> 	id = IntCol()
> 	kindName = StringCol()
> 	persons = MultipleJoin('person')
> 
> class person(SQLObject):
> 	id = IntCol()
> 	name = StringCol()
> 	rankID = ForeignKey('rank')
> 	kindID = ForeignKey('kind')
> 	
> 
> What's the best way to get title and kindName instead rankID and kindID
> if i do person.get(1).select() (or else)?

class rank(SQLObject):
	id = IntCol()
	title = StringCol()
	persons = MultipleJoin('person', joinColumn="rank_id")

class kind(SQLObject):
	id = IntCol()
	kindName = StringCol()
	persons = MultipleJoin('person', joinColumn="kind_id")

class person(SQLObject):
	id = IntCol()
	name = StringCol()
	rank = ForeignKey('rank')
	kind = ForeignKey('kind')

person.get(1).rank

Oleg.
-- 
     Oleg Broytmann            http://phd.pp.ru/            ph...@ph...
           Programmers don't die, they just GOSUB without RETURN.