sqlobject-discuss

[SQLObject] One to many relationships manipulation

[Robert L. <ro...@le...>]

Warning SQLObject (and Python) newbie question follows:

I have a requirement to display the data from the 'many' side of a 
relationship (e.g. the addresses in a person-address) in an html table, 
where each column in the html table is one row from the 'many' table 
(i.e. each property of the address object is displayed in a new row of 
the same column). I have a working solution but it is not pretty and I 
wonder if there is an efficient SQLObject (or Pythonic way) to do this?

An illustration may help. I need to go from:

Person
   Address1(street, city, state, zip)
   Address2(street, city, state, zip)
   Address3(street, city, state, zip)
   Address4(street, city, state, zip)

to:

Person
   Address1.street  Address2.street  Address3.street Address4.street
   Address1.city    Address2.city    Address3.city   Address4.city
   Address1.state   Address2.state   Address3.state  Address4.state
   Address1.zip     Address2.zip     Address3.zip    Address4.zip


Robert

[SQLObject] Re: One to many relationships manipulation

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

On 16 Aug 2004, Robert Leftwich said:

> I have a requirement to display the data from the 'many' side of a 
> relationship (e.g. the addresses in a person-address) in an html table, 
> where each column in the html table is one row from the 'many' table 
> (i.e. each property of the address object is displayed in a new row of 
> the same column).

Hmm... How about adding a __str__() function to the Address class like 
this:

class Address(SQLObject):
    [... stuff here ...]

    def __str__(cls):
        return "%(street)s\n%(city)s, %(state)s    %(zip)s" % cls.
__dict__


Then, whenever you tried to use an address object as a string, it would 
become:

Street
City, State     ZIP

And you could just merrily print each Address object! :D

[SQLObject] Re: One to many relationships manipulation

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

On 16 Aug 2004, Chris Gahan said:

> class Address(SQLObject):
>     [... stuff here ...]
> 
>     def __str__(cls):
>         return "%(street)s\n%(city)s, %(state)s    %(zip)s" % cls.
> __dict__
> 

Oops, I should've used "self" instead of "cls". Otherwise, it's good. :)

Re: [SQLObject] One to many relationships manipulation

[Ian B. <ia...@co...>]

Robert Leftwich wrote:
> Warning SQLObject (and Python) newbie question follows:
> 
> I have a requirement to display the data from the 'many' side of a 
> relationship (e.g. the addresses in a person-address) in an html table, 
> where each column in the html table is one row from the 'many' table 
> (i.e. each property of the address object is displayed in a new row of 
> the same column). I have a working solution but it is not pretty and I 
> wonder if there is an efficient SQLObject (or Pythonic way) to do this?
> 
> An illustration may help. I need to go from:
> 
> Person
>   Address1(street, city, state, zip)
>   Address2(street, city, state, zip)
>   Address3(street, city, state, zip)
>   Address4(street, city, state, zip)
> 
> to:
> 
> Person
>   Address1.street  Address2.street  Address3.street Address4.street
>   Address1.city    Address2.city    Address3.city   Address4.city
>   Address1.state   Address2.state   Address3.state  Address4.state
>   Address1.zip     Address2.zip     Address3.zip    Address4.zip

You'll simply have to do this as a loop, like:

addresses = Person.addresses()

for address in addresses:
     print address.street
for address in addresses:
     print address.city

etc.  You could be fancy and do:

for attr in ['street', 'city', 'state', 'zip']:
     for address in addresses:
         print getattr(address, attr)

-- 
Ian Bicking  /  ia...@co...  / http://blog.ianbicking.org