Rails - Jul 2006 - RoR data models ( extreme newbie question)

I''m pretty new to Rails too and obivously I don''t know your
previous
experience but I''d recommend looking at the ''Agile Web
Devlopment with
Rails'' book which you can find here.

http://www.pragmaticprogrammer.com/titles/rails2/

It''s really helped me get started, and the fact that the PDF version is
so cheap, there''s no reason not to get it!

Henry

-- 
Posted via http://www.ruby-forum.com/.

Hi Martyn,

The new way of creating db tables is to use migrations, but before we 
walk down that road, let me tell ya about the old way, which still works 
just fine.

Tables are always the plural name of the models they represent, so if 
you are going to have a user model then you have to have a users table 
and if you are going to have a product model you would name your db 
table products.

In order to make your life easier, and being the lazy programmer I am, I 
love easier, each table needs to have a primary key called id which is 
auto increment, an amazing ammount of rails automagic depends on this 
tiny step.

You can cruise on over to: 
http://www.ocf.berkeley.edu/~jday/wiki/index.php?DevelopmentEnvironment

and that should fill you in.  Hope this helps.

Phil

-- 
Posted via http://www.ruby-forum.com/.

Sorry for asking this but I am keen to get on and build an app based on 
RoR and have had a look around at FAQa and the like with no immediate 
sucess.

What I am looking for is an explainantion of the rules/requirements for 
table/index/coulumn names with RoR. RoR appears to have a set of 
expected naming conventions which it would appear you can over ride but 
it would seems a hell of a lot easier if I could model my db to match 
what RoR wnats and he presto! I am in business.

If anyone could point me to such a page/doc I would appreciate it

Leggs

-- 
Posted via http://www.ruby-forum.com/.

Martyn Bedford wrote:
> So if I have my object I create a table called object(s) and create a 
> primary key called id, so good so far, now what I need to do is create 
> joins and foriegn keys to other tables, I have seen this working in a 
> few examples but I am lost as to the naming conventions for this.

This is pretty easy ---

There are two basic ways to relate in ruby has_many or has_one and 
belongs_to.  As always, there are options to handle complex cases.

Check the api docs for these functions and much will become clear. 
http://api.rubyonrails.org/

Basically the difference is where the foreign key lives.  In belongs_to, 
it is in the table for the model.

For example:

If you have a cities table and your object belongs_to a :city, you will 
have a city_id field in the objects table.  Note the plural/singluar - 
the table is plural but the foreign key is singluar.

If you have a has_many or has_one relationship then the foreign key 
lives in the other table.  So to take the example further, in the City 
model definition, you would put "has_many :objects"  -- no futher work
needed.  Now the following should be true for any city with at least one 
object:  city.objects[0].city == city.


Steven

-- 
Posted via http://www.ruby-forum.com/.

Phil Peterman wrote:
> Hi Martyn,
> 
> The new way of creating db tables is to use migrations, but before we 
> walk down that road, let me tell ya about the old way, which still works 
> just fine.
> 
> Tables are always the plural name of the models they represent, so if 
> you are going to have a user model then you have to have a users table 
> and if you are going to have a product model you would name your db 
> table products.
> 
> In order to make your life easier, and being the lazy programmer I am, I 
> love easier, each table needs to have a primary key called id which is 
> auto increment, an amazing ammount of rails automagic depends on this 
> tiny step.
> 
> You can cruise on over to: 
> http://www.ocf.berkeley.edu/~jday/wiki/index.php?DevelopmentEnvironment
> 
> and that should fill you in.  Hope this helps.
> 
> Phil
Thanks everyone for your answers, as with any answer it invenitably 
leads to another question.

So if I have my object I create a table called object(s) and create a 
primary key called id, so good so far, now what I need to do is create 
joins and foriegn keys to other tables, I have seen this working in a 
few examples but I am lost as to the naming conventions for this.

Martyn

-- 
Posted via http://www.ruby-forum.com/.

Martyn Bedford wrote:
> Sorry for asking this but I am keen to get on and build an app based on 
> RoR and have had a look around at FAQa and the like with no immediate 
> sucess.
> 
> What I am looking for is an explainantion of the rules/requirements for 
> table/index/coulumn names with RoR. RoR appears to have a set of 
> expected naming conventions which it would appear you can over ride but 
> it would seems a hell of a lot easier if I could model my db to match 
> what RoR wnats and he presto! I am in business.
> 
> If anyone could point me to such a page/doc I would appreciate it
> 
> Leggs
If you want to take advantage of the Rails framework, then you may name
your database table names as something plural. For example if you have a
database table named as departments then you should create a model class
named as department. For more information visit
http://www.onlamp.com/pub/a/onlamp/2005/01/20/rails.html?page=2

regards,
Prasad,
Genie Interactive, Bangalore

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