gistfile1.txt

SELECT
  u.id  AS user_id,
  c.id  AS led_campaign_id,
  pc.id AS personal_campaign_id,
  c2.id AS personal_campaign_campaign_id,
  c3.id AS followed_campaign_id

  FROM users u
    LEFT OUTER JOIN campaigns c           ON u.id = c.creator_id
    LEFT OUTER JOIN photos p              ON c.photo_id = p.id

    LEFT OUTER JOIN personal_campaigns pc ON u.id = pc.creator_id AND pc.campaign_id != c.id
    LEFT OUTER JOIN campaigns c2          ON pc.campaign_id = c2.id
    LEFT OUTER JOIN activities a          ON a.campaign_id = c2.id

    LEFT OUTER JOIN follows f             ON u.id = f.user_id
    LEFT OUTER JOIN campaigns c3          ON f.followed_id = c3.id
    LEFT OUTER JOIN photos p2             ON c3.photo_id = p2.id

  WHERE u.id = 2329
    AND f.followed_type = 'Campaign'

  ORDER BY
    c.created_at  DESC,
    a.deadline    ASC,
    c3.created_at DESC

  LIMIT 10, 20 \G;

SELECT
  c.id, pc.id

  FROM
    campaigns c

  LEFT OUTER JOIN follows f
    ON f.followed_id = c.id AND f.user_id = 2329

  LEFT OUTER JOIN personal_campaigns pc
    ON pc.creator_id = 2329 AND pc.campaign_id = c.id

  WHERE
    c.creator_id = 2329 OR f.id

  -- ORDER BY ???
;

Campaign.select('campaigns.*, pc.id').
  joins('LEFT OUTER JOIN follows f ON f.followed_id = campaigns.id AND f.user_id = 2329').
  joins('LEFT OUTER JOIN personal_campaigns pc ON pc.creator_id = 2329 AND pc.campaign_id = campaigns.id').
  where('campaigns.creator_id = 2329 OR f.id').
  limit(100).
  offset(1000).
  includes(:photos)

select * from photos where campaign_id in (1,2,3,4,5,6,7);


campaigns = Campaign.select_from_sql([ ...  ])
Preloader.new(campaigns, [:photos]).run