mysql join query to ruby on Rails

Question

I have a join query in mysql

SELECT c.*, r.*
FROM court c
LEFT JOIN reservations r
      ON c.`id` = r.`court_id`
     AND `start_time` < '2016-01-20 11:30:00'
     AND `end_time`   > '2016-01-20 11:00:00'
WHERE  `start_time` IS NULL;

For reference:

reservations.rb 
belongs_to court
fields: start_time,end_time, court_id

courts.rb
has_many reservations
fields: id, name

I've tried to convert this to rails, but can't seem to do it. I've tried Courts.join(:reservations).on("start_time<'2016-01-20 11:00:00'") but this doesn't work

Answer 1

The converted version will be:

Courts.joins('LEFT JOIN reservations ON courts.id = reservations.id')
      .where('reservations.start_time < ? AND reservations.end_time > ?', '2016-01-20 11:30:00', '2016-01-20 11:00:00')
      .where(courts: {start_time: nil})

Note that joins in default is INNER JOIN , so we need to explicitly point out LEFT JOIN