Rails 3 - Find by name instead of id

开发者_如何学Python

I'm trying to learn RoR, building my first app, a basic inventory application. I've tried searching around but could not find the correct syntax, so I thought I would ask.

Here's my set up:

Model

class Item < ActiveRecord::Base
belongs_to :supplier

class Supplier < ActiveRecord::Base
has_many :items

Items Controller

@items = Item.find_all_by_supplier_id '1'

This will return the data that I want, but I was hoping to input the supplier name into the controller so that if the ID does not match up it will still work properly.

Hope that's enough info, thanks!

---

You could invert your method bit and try:

@items = Supplier.find_by_name('THE NAME').items

Rails creates dynamic find_by_* and find_all_by_* methods for searching. Instead of retrieving items by the supplier_id, I recommend you let rails do this for you with the associations you have set up as in the code snippet above. Internally, this still uses the supplier_id, but rails is handling the process instead of you.

The inverse of this is also possible, so if you have an item and want the supplier, you can do:

Item.find(1).supplier

---

@items = Item.joins(:suplier).where(:suplier => { :name => "Suplier name" })

---

Supplier.find_by_colname(params[:name])

Where colname is the name of Supplier table column in which we want to check our parameter value. In rails we can just append column name with the find_by_ as shown above and rails will show you it's magic ;) . Here is the reference in Doc