Fred & Rob - thanks for the help!
-Gavin
On Oct 7, 10:55 am, Rob Biedenharn <[EMAIL PROTECTED]>
wrote:
> On Oct 7, 2008, at 10:43 AM, gaveeno wrote:
>
>
>
> > Rob - you mentioned that you should have indexes on your *_id columns
> > if they're used in has_many relationships. When I created my
> > migrations for tables containing *_id columns, I set these columns up
> > like in the following example:
>
> > create_table :branches do |t|
> > t.integer :company_id, :null => false, :options => "CONSTRAINT
> > fk_branch_company REFERENCES companies(id)"
> > ...
>
> > How would I add an index to an existing column? And, for future
> > tables that I'll be creating, how would I set up a new column with an
> > index?
>
> > Thanks!
> > Gavin
>
> add_index :branches, :company_id
>
> Add a :name option if you like (or if you use a database adapter that
> has a bit of trouble in this area :-)
>
> some_company.branches causes something like:
>
> SELECT * FROM branches WHERE company_id = #{some_company.id}
>
> So you want an index on branches.company_id to make this fast.
>
> -Rob
>
> > On Oct 6, 5:13 pm, Rob Biedenharn <[EMAIL PROTECTED]> wrote:
> >> On Oct 6, 2008, at 5:06 PM, elioncho wrote:
>
> >>> Hello,
>
> >>> I have a dilemma. Should I create foreign keys on my database or
> >>> should I let the app models do all the work?
>
> >>> Thanks,
>
> >>> Elioncho
>
> >> If the Rails app is the only thing hitting the database, then let
> >> ActiveRecord handle it.
>
> >> If you're paranoid or there are other apps updating the database,
> >> then
> >> go for the safety-net.
>
> >> In any case, you certainly want indexes on your *_id columns if there
> >> is a has_many that uses it. (I.e., on the bars.foo_id column if Foo
> >> has_many :bars)
>
> >> -Rob
>
> >> Rob Biedenharn http://agileconsultingllc.com
> >> [EMAIL PROTECTED]
>
>
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