Question

I have a model called Person that has_one Address. Person has fields like first_name and last_name; Address has postal_code, state, and so on.

I know how to use finders to find all people with a certain name; that’s Person.find_by_last_name("Smith"). But how do I find all people where:

• their first_name is “Bob”; and
• their last_name is “Smith”; and
• who have addresses with a city of ‘Foobar’; and
• who have addresses with a postal_code of ‘12345’

Answer 1

When you’re looking for exact values, you can pass a hash of the values you’d like to match to where. Each referenced model is its own nested hash, as in the example below:

Person.
  where(:first_name => 'Bob').
  where(:last_name => 'Smith').
  where(:address => { :postal_code => '12345' }).   # queries associated Address
  where(:address => { :city => 'Foobar' })          # queries associated Address