newbie question - How can I run the following Query in ActiveRecord ?

rubyonrails-talk
1

I'm totally rails newbie, and just started it a couple of days ago moving from PHP, so I've the following query, and want to know how can I do it using ActiveRecord

SELECT `sites`.*, `snapshots`.*, `technologies`.* FROM `sites`, `snapshots`, `technologies` WHERE `sites`.id = '1' AND `snapshots`.`site_id` = `sites`.`id` AND `technologies`.`snapshot_id` = `snapshots`.`id`

2

I'm totally rails newbie, and just started it a couple of days ago moving from PHP, so I've the following query, and want to know how can I do it using ActiveRecord

SELECT `sites`.*, `snapshots`.*, `technologies`.* FROM `sites`, `snapshots`, `technologies` WHERE `sites`.id = '1' AND `snapshots`.`site_id` = `sites`.`id` AND `technologies`.`snapshot_id` = `snapshots`.`id`

Don't think about queries, think about relationships. If you setup the has_many and belongs_to relationships then if you have a Site in @site then its snapshots are @sites.snapshots and for a given snapshot then its technologies are snapshot.technologies. Let Rails worry about the queries.

Any newcomer is well advised to work through some tutorials to understand what rails can do. railstutorial.org is good and is free to use online. Also work through the Rails Guides. Make sure any tutorial you use is for the right version of Rails.

Colin

3

I think what you are trying to do is joins

if your associations are set correctly, then something like below should work

Site.joins(:snapshots).joins(:technologies).where(“sites.id=1”)

Note: in the where clause, you cannot use :id=>1 because :id with the joined tables will be ambigious… you have to state explicitly the table of which the id to be used