I apologize if the answer to this question is going to be rudimentary,
but I am thus far stymied by the information I have found on the web.
This seems like it should be simple, but I haven't really found an
example of how to do this yet.
I have a model called Account which has a belongs_to reference to
another model, User, as below:
class Account < ActiveRecord::Base
belongs_to :primary_user, :class_name =>
"User", :foreign_key => "primary_user"
end
The User model has a property "last_name" and the Account model has a
property "account_name". I want to create a query to find all
accounts by the account's name (account.account_name) and by the
primary user's last name (account.primary_user.last_name). Is there a
best-practice way to write a query like this?
User
belongs_to :account
# no reference to an account for which this user is the primary/
administrative user
I am trying to find all accounts where the account name equals some
query parameter, and the account's primary user's last name equals a
query parameter. If I was going to do this in Java with Hibernate,
the query would look like this:
Criteria accountCriteria = session.createCriteria(Account.class);
// Create restriction to search on the account's name
accountCriteria.add(Restrictions.like("accountName",
searchParam1+"%"));
//Create restriction on the account's primary user and search on the
user's last name in addition to the Account's name
Criteria userCriteria = accountCriteria.createCriteria("primaryUser");
userCriteria.add(Restrictions.like("lastName", searchParam2+"%"));
List results = accountCriteria.list();
And this is not a legacy schema, and it is quite possible that it
sucks. I am historically a Java guy who thinks in object models and
creates a schema that exists only to persist the object model. If you
have any thoughts on how to model this relationship more easily, I am
all ears.
Thanks for responding, hopefully this provides enough clarification.
There is nothing stopping you from havning a has_many in the user class
to use the scopeing that comes for free when you use the user object to
start you queries.
I find that using an objects association collection to scope the
objects to that user is one of the easier ways to do it in rails.
@user.collection_of_things
Thanks for the responses, all - I appreciate the timely responses from
the community.
That approach works, but you then run into the N+1 query issue do you
not?. Every time I need to search for an account, I also need to
search for a user. Probably it won't make much difference with the
size of my app, but if anyone knows a way to get this done in a single
query, I feel like that would probably be best. But that approach
will work, so thanks for the tip.
But this should work.