How to add conditional where clauses in rails

Question

I am a rails newbie and am trying to perform a search on a table with rails, and i\'m just using my sql knowledge to do this. But this just doesn\'t seems like rails or ruby

Answer 1

You can apply multiple where calls to a query so you can build your base query:

query = User.joins(...)
            .group(...)
            .select(...)
            .where('users.id = :user_id', :user_id => self.id)

and then add another where call depending on your date interval:

if(begin_date && end_date)
  query = query.where(:created_at => begin_date .. end_date)
  # or where('created_at between :begin_date and :end_date', :begin_date => begin_date, :end_date => end_date)
elsif(begin_date)
  query = query.where('created_at >= :begin_date', :begin_date => begin_date)
elsif(end_date)
  query = query.where('created_at <= :end_date', :end_date => end_date)
end

Each where call adds another piece to your overall WHERE clause using AND so something like:

q = M.where(a).where(b).where(c)

is the same as saying WHERE a AND b AND c.

Answer 2

I cant think of a great reason why you would actually want to generate SQL in your code. Active record seems like a much more efficient solution for your needs, unless there is a reason why you cant use that.

Link explaining how to join tables with active record