title: When to use an ORM (Sequel, Datamapper, AR, etc.) vs. pure SQL for querying
body: <p>A colleague of mine is currently designing SQL queries like the one below to produce reports, which are displayed in excel files through an external data query.
  At present, only reporting processes on the DB are required (no CRUD operations).</p>
  
  <p>I am trying to convince him that it would be better to use a ruby ORM in order to be able to display the data in a rails/sinatra app.</p>
  
  <p>Despite the obvious advantages in displaying the data, what advantages are there for him in learning to use an ORM like Sequel or Datamapper?</p>
  
  <p>The SQL queries he is writing are clearly quite complex, and being relatively new to SQL, he often complains that it is very time-consuming and confusing. 
  Is it possible to write extremely complex queries with an ORM? and if so, which is the most suitable(I have heard Sequel is good for legacy dbs)? and what are the advantages of learning ruby and using an ORM versus sticking with plain SQL, in making complex database queries?</p>