按SQL排序(Rails Order by SQL)

 我有一个TraitQuestion模型，它具有许多特征或答案 - 每个特征或答案都有一个值，例如1,2,3或-3105（对于以上都不是）。 我无法更改这些值，因为它们是外部API所必需的。 
 
 我想按价值订购它们，但是当我这样做时，-3105的答案显示在顶部，即使它表示“以上都不是”： 
 
Answer 4 = -3105
Answer 1 = 1
Answer 2 = 2
Answer 3 = 3
 
 关于我们如何订购它的任何想法，以便它 
 
1
2
3
-3105?
 
 我是SQL的新手，但似乎我应该能够做到这样的事情： 
 
@trait_question.traits.order('CASE WHEN value AS int > 0 then 1 ELSE 0 END')
 
 但这不起作用。 任何想法我如何调整顺序调用SQL，以便它将按正确的顺序排序？ 
 
 编辑：这是通过亚马逊AWS的Postgresql 9.4.1 

I have a TraitQuestion model that have a number of traits or answers - each of which has a value such as 1, 2, 3, or -3105 (for none of the above). I can't change these values because they are required for an external API.
 
I'd like to order them by the value, but when I do that, the answer with -3105 shows up at the top even though it says "None of the above":
 
Answer 4 = -3105
Answer 1 = 1
Answer 2 = 2
Answer 3 = 3
 
Any idea on how we could order this so that it's 
 
1
2
3
-3105?
 
I'm pretty new to SQL but it seems like I should be able to do something like this:
 
@trait_question.traits.order('CASE WHEN value AS int > 0 then 1 ELSE 0 END')
 
But that doesn't work. Any ideas how I can adjust the order call SQL such that it would order them in the correct order?
 
EDIT: This is Postgresql 9.4.1 via Amazon AWS

原文：https://stackoverflow.com/questions/36099163