Ruby-on-rails Rails - 用 2 个字段查找？
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Rails - Find By with 2 fields?
提问by AnApprentice
I have the following in a controller
我在控制器中有以下内容
def update
@permission = Permission.find_by_user_id(params[:user_id])
But I want it to also find by another param, project_id
但我希望它也能通过另一个参数找到， project_id
How can I do something like this in Rails?
我怎样才能在 Rails 中做这样的事情？
@permission = Permission.find_by_user_id_and_project_id(params[:user_id],params[:user_id])
回答by Fred Willmore
Rails 4 introduces the find_by method:
Rails 4 引入了 find_by 方法：
Permission.find_by(user_id: params[:user_id], project_id: params[:project_id])
回答by Jesse Wolgamott
Yes, you can do finds in a bunch of ways.
是的，您可以通过多种方式进行查找。
Your example below works:
您下面的示例有效：
@permission = Permission.find_by_user_id_and_project_id(params[:user_id],params[:project_id])
@permission = Permission.find_by_user_id_and_project_id(params[:user_id],params[:project_id])
-- Note your example had two user_ids
-- 注意你的例子有两个 user_ids
In rails 2.x you can also use conditions
在 rails 2.x 中，您还可以使用条件
@permission = Permission.find(:conditions=>["user_id=? and project_id=?", params[:user_id], params[:project_id]])
And in Rails 3, you can be cool like:
在 Rails 3 中，你可以很酷：
@permission = Permission.where(:user_id=>params[:user_id]).where(:project_id=>params[:project_id]).first
回答by Jacob Relkin
Try this:
尝试这个：
@permission = Permission.find(:conditions => ['user_id = ? and project_id = ?', params[:user_id], params[:project_id]])
回答by DGM
Rails 3 way with scopes:
带作用域的 Rails 3 方式：
scope :by_user_id_and_project_id, lambda {|user_id,project_id|
where(:user_id=>user_id).where(:project_id=>project_id])
}
And then you can use it like:
然后你可以像这样使用它：
@permission = Permission.by_user_id_and_project_id(params[:user_id],params[:project_id])
