问题描述
当我有一组 id 时，比如
When I have array of ids, like
ids = [2,3,5]
我表演
Comment.find(ids)
一切正常.但是当有不存在的 id 时，我会得到一个例外.当我获得与某个过滤器匹配的 ID 列表而不是执行类似的操作时，通常会发生这种情况
everything works fine. But when there is id that doesn't exist, I get an exception. This occurs generaly when I get list of IDs that match some filter and than I do something like
current_user.comments.find(ids)
这次我可能有一个有效的评论 ID，但是它不属于给定的用户，所以没有找到它，我得到了一个例外.
This time I may have a valid comment ID, which however does not belong to given User, so it is not found and I get an exception.
我试过 find(:all, ids)，但它返回所有记录.
I've tried find(:all, ids), but it returns all of the records.
我现在唯一能做的就是
current_user.comments.select { |c| ids.include?(c.id) }
但在我看来，这是一种非常低效的解决方案.
But that seems to me like super inefficient solution.
是否有更好的方法来选择数组中的 ID 而不会在不存在的记录上出现异常?
Is there better way to select ID in Array without getting exception on non-existing record?
推荐答案
如果只是为了避免您担心的异常，那么find_all_by.."系列函数不会抛出异常.
If it is just avoiding the exception you are worried about, the "find_all_by.." family of functions works without throwing exceptions.
Comment.find_all_by_id([2, 3, 5])
即使某些 ID 不存在也能工作.这适用于
will work even if some of the ids don't exist. This works in the
user.comments.find_all_by_id(potentially_nonexistent_ids)
案例也是如此.
Comment.where(id: [2, 3, 5])
这篇关于如何在Array Rails ActiveRecord中选择where ID无一例外的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！