如何将find_by_sql语句翻译成named_scope？
如何将find_by_sql语句翻译成named_scope？
提问于 2010-05-25 05:51:50
如何将以下代码转换为named_scope？
def self.commentors(cutoff=0)
return User.find_by_sql("select users.*, count(*) as total_comments from users, comments
where (users.id = comments.user_id) and (comments.public_comment = 1) and (comments.aasm_state = 'posted') and (comments.talkboard_user_id is null)
group by users.id having total_comments > #{cutoff} order by total_comments desc")
end这是我现在所拥有的，但它似乎不起作用：
named_scope :commentors, lambda { |count=0|
{ :select => "users.*, count(*) as total_comments",
:joins => :comments,
:conditions => { :comments => { :public_comment => 1, :aasm_state => 'posted', :talkboard_user_id => nil} },
:group => "users.id",
:having => "total_comments > #{count.to_i}",
:order => "total_comments desc"
}
}最终，这就是有效的方法；
named_scope :commentors, lambda { |*args|
{ :select => 'users.*, count(*) as total_comments',
:joins => :comments,
:conditions => { :comments => { :public_comment => 1, :aasm_state => 'posted', :talkboard_user_id => nil} },
:group => 'users.id',
:having => ['total_comments > ?', args.first || 0],
:order => 'total_comments desc' }
} 回答 1
Stack Overflow用户
回答已采纳
发布于 2010-05-25 06:54:15
您遇到的问题是因为您使用comments的内部联接替换了从users, comments进行选择。要将SQL正确转换为named_scope，请使用以下命令：
named_scope :commentors, lambda { |cutoff|
{ :select => 'users.*, count(*) as total_comments',
:conditions => { :comments => { :public_comment => 1, :aasm_state => 'posted', :talkboard_user_id => nil } },
:from => 'users, comments',
:group => 'users.id',
:having => ['total_comments > ?', cutoff],
:order => 'total_comments desc' } }而且您不能为lambda参数设置默认值，因此您不能使用|cutoff = 0|。
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/2900588
复制相关文章
相似问题
腾讯云开发者
