Rails - Feb 2012 - Using a string column instead of an id column to differentiate records

How do you decide whether to use a string column or an id column to 
differentiate between different types of records?

Suppose you have a relationships table that maps users to forums. The 
possible relationships can be: subscriber, moderator, owner.

When does it make sense to move those relationship types to their own table 
and reference them through a relationship_type_id column? What''s the 
criteria? Or is it better to use a string column to differentiate them?

-- 
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To view this discussion on the web visit
https://groups.google.com/d/msg/rubyonrails-talk/-/t2scvYNus4UJ.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en.

On Feb 28, 2012, at 2:09 PM, Mohamad El-Husseini wrote:
> How do you decide whether to use a string column or an id column to
differentiate between different types of records?
> 
> Suppose you have a relationships table that maps users to forums. The
possible relationships can be: subscriber, moderator, owner.
> 
> When does it make sense to move those relationship types to their own table
and reference them through a relationship_type_id column? What''s the
criteria? Or is it better to use a string column to differentiate them?
Does the client/admin want to be able to change the names or number of these
groups, or are you going to be updating it (and thus could make these sorts of
code-level changes) when the management winds change?

For a few options such as you have here, there''s no reason to do it,
IMO, since with an index, it''s going to be just as fast or faster than
joining another table by a numerical lookup. I would pull these options out into
a constant so you only have one place to type them, too.

Walter

-- 
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk+unsubscribe@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en.