我在这里没有做任何想法;没有。作为一个菜鸟，有人可以向我解释为什么会这样吗？我正在关注BigDecimal并收到错误：
Rails控制台：
<form:xxx>所以我想，让我安装{{3}}，一切都会好的。不，同样的问题。这是SELECT d.document_id,
d.document_name,
d.document_amount,
r1.requirement_name AS req_1,
r2.requirement_name AS req_2,
r3.requirement_name AS req_3,
r4.requirement_name AS req_4,
r5.requirement_name AS req_5,
r6.requirement_name AS req_6,
r7.requirement_name AS req_7
FROM documents AS d,
requirements AS r1,
requirements AS r2,
requirements AS r3,
requirements AS r4,
requirements AS r5,
requirements AS r6,
requirements AS r7
WHERE d.req_1 = r1.requirement_id
AND d.req_2 = r2.requirement_id
AND d.req_3 = r3.requirement_id
AND d.req_4 = r4.requirement_id
AND d.req_5 = r5.requirement_id
AND d.req_6 = r6.requirement_id
AND d.req_7 = r7.requirement_id
的问题吗？它与我使用的Rails 5有任何关联吗？我在控制台，而不是Rails。感谢。
堆栈追踪：
require 'bigdecimal' #=> false
sum = BigDecimal.new("0") #=> stack level too deep