sqlobject-discuss

[SQLObject] defining 1 to many relationships

[<jo...@cy...>]

Dear Group,

i just started looking at SQLObject and i ahve a question.  I am trying to see if it will work with a database that I already have developed with data in MySQL.  I have two tables images and di (donating investigator) and there is a 1 to many relationship between di and images.  The images table contains a field called source_di which links to the di id field which is also the key for the di table. i defined the table classes like this:

class Images(SQLObject):
    _idName = 'uin'
    _fromDatabase  = True
    sourceDi = ForeignKey('Di')

class Di(SQLObject):
    _fromDatabase = True
    _idName = 'id'
    Images = ForeignKey('Images')


When I try and run

images = Images.select()
for i in images:
    print i.uin

but this does not work, and the error message says that there is no column called imags.source_di_id

am I out of luck unless I want to redesign the database?

Thanks for any and all help

Jose

[SQLObject] Re: defining 1 to many relationships

[Chris G. <ch...@il...>]

>The images table contains a field called source_di which links to the di id
field which is also the key for the di table. i defined the table classes
like this:
>
> class Images(SQLObject):
>     _idName = 'uin'
>     _fromDatabase  = True
>     sourceDi = ForeignKey('Di')
>
> class Di(SQLObject):
>     _fromDatabase = True
>     _idName = 'id'
>     Images = ForeignKey('Images')

The problem is that a ForeignKey column gives you back one object, since
it's for references to a single index in another table. So, when you access
Images in Di, it ain't gunna work.

You have to make Images = MultipleJoin('Images'). You may also have to go
into SQL and rename the column in the Images table that references back to
Di, although I'm not certain about this. I am a bit new to SQLObject myself.
:)

= Chris Gahan =============
  (ch...@il...)