title: Inner joins vs left joins
body: <p>I have been using <code>LEFT JOIN</code> in all my queries so far and just came across the ability to specify multiple tables in <code>FROM</code> which gives the same result. I didn't know you could refer to multiple tables in <code>from</code> and do joins in <code>where</code>. I used <code>where</code> strictly for filtering data and kept <code>from</code> to one table.</p>
  <p>Where can I learn more about option 2 and when it is more useful? Or should I stick to option 1?</p>
  <p><strong>Option 1: LEFT JOIN</strong></p>
  <pre><code>select
  f.title,
  count(r.rental_id)
  from rental r
  left join inventory i on i.inventory_id=r.inventory_id
  left join film f on f.film_id=i.film_id
  Group by title
  order by count(r.rental_id) desc
  </code></pre>
  <p><strong>Option 2: JOIN in FROM</strong></p>
  <pre><code>select
  f.title,
  count(r.rental_id)
  from film f, rental r, inventory i
  where f.film_id=i.film_id
  and  i.inventory_id=r.inventory_id
  group by 1
  order by count(r.rental_id) desc
  </code></pre>