将sql查询转换为rails 2.3.5兼容

Question

下面是我的SQL查询

SELECT individuals.* FROM ( select children.*  FROM checkins, children WHERE 
checkins.child_id = children.id AND checkins.event_id = 1234 ) temp, 
individuals WHERE temp.individual_id = individuals.id 
ORDER BY individuals.firstname;

可以将其转换为rails 2.3.5兼容（活动记录查找方法）

[编辑]

SELECT individuals.* FROM ( SELECT children.*  
FROM checkins INNER JOIN children 
ON checkins.child_id = children.id WHERE checkins.event_id = 1234 ) temp 
INNER JOIN individuals ON temp.individual_id = individuals.id ORDER BY
individuals.firstname;

Answer 1

Individual.find(:all, :joins => {:children => :checkins}, :conditions => 'checkins.event_id = 1234', :order => 'individuals.firstname')