如何毫无例外地选择Array Rails ActiveRecord中的ID [英] How to select where ID in Array Rails ActiveRecord without exception

问题描述

当我有一个 id 数组时，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，我得到一个异常.这通常发生在我获得与某个过滤器匹配的 ID 列表并且比我执行类似的操作时

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，但它不属于给定的用户，所以没有找到它，我得到了一个异常.

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)，但是它返回了所有的记录.

I've tried find(:all, ids), but it returns all of the records.

我现在唯一能做到的就是

The only way I can do it now is

current_user.comments.select { |c| ids.include?(c.id) }

但在我看来，这似乎是一种超级低效的解决方案.

But that seems to me like super inefficient solution.

有没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

如果只是避免您担心的异常，find_all_by.."系列函数可以正常工作而不会抛出异常.

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 不存在也可以工作.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)

情况也是如此.

Comment.where(id: [2, 3, 5])

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