ruby-on-rails - rails : check if ID doesn't exist in controller?

Question

是否可以执行以下操作:

if @user = User.friendly.find(params[:id])
    // logic here
else
    // do something if user doesn't exist
end

由于某种原因，这会引发以下错误:

ActiveRecord::RecordNotFound

Answer 1

This is as expected .

[The] RecordNotFound [exception is raised if] No record responded to the find method. Either the row with the given ID doesn't exist or the row didn't meet the additional restrictions. Some find calls [like the find_by* methods] do not raise this exception to signal nothing was found ..

使用find_by_id(或find_by)，如果未找到该项目，将返回nil:

friendly.find_by_id params[:id]
friendly.find_by id: params[:id]

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另请参阅:Rails find getting ActiveRecord::RecordNotFound