Re: [Rails] using multiple joins in queries

On Mar 20, 2013, at 6:04 PM, John Merlino wrote:

> I have this query:
>
> Report.
> joins(:alerts).
> joins(:alert_code).

I think that you're looking for 'includes' rather than 'joins' for these associations.

Report.includes({:alerts => :alert_code}).

To use joins, you would have to supply more SQL-ish clauses, not symbols for the associations.

http://apidock.com/rails/v3.2.8/ActiveRecord/QueryMethods/joins
http://apidock.com/rails/v3.2.8/ActiveRecord/QueryMethods/includes

-Rob

> where(:unit_id => unit_id).
> where{time < my{self.time}}.
> where("alert_codes.name LIKE ?", "%Inside virtual
> fence%").
> order("reports.time DESC").first
>
> Basically, it breaks:
>
> ActiveRecord::ConfigurationError (Association named 'alert_code' was
> not found; perhaps you misspelled it?):
>
>
> My associations look like this:
>
> report has_many alerts
> alert belongs_to :alert_code, :foreign_key => :code
>
> I am trying to get the first report whose alerts belongs to alert_code
> whose name is "inside virtual fence". So there are 3 associations
> here. Trying to establish the connection.
>
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