我在路线'memorisation'
有一个视图,它有一个CSV文件类型的文件导入。当我运行导入时,所有的更改似乎都适用于所有139条记录。但是,我仍然收到错误。
NoMethodError in MemorisationController#import
undefined method `[]' for nil:NilClass
这是我的控制器方法:
def import
require 'csv'
all_targets = MemoTarget.order(:id).includes(:memo_level).map do |t|
{
:id => t.id,
:target => t.target_number,
:level => t.memo_level.level_number
}
end
CSV.foreach(params[:file].path, headers: true) do |row|
the_target = MemoTest.create do |test|
test.student_id = row["student_id"]
test.teacher_id = session[:user_id]
test.memo_target_id = all_targets.find {|t| t[:level] == row["memo_level"].to_i and t[:target] == row["memo_target"].to_i}[:id]
test.result = true
end
end
redirect_to '/memorisation', notice: 'Student memorisation current targets imported'
end
行test.memo_target_id = all_targets.find {|t| t[:level] == row["memo_level"].to_i and t[:target] == row["memo_target"].to_i}[:id]
正在抛出错误。
在我的服务器日志中,正在进行所有预期的更改,如SQL COMMITs
所示。提交后,控制器应重定向回memorisation
页面。
...
(0.7ms) COMMIT
(0.3ms) BEGIN
SQL (0.5ms) INSERT INTO "memo_tests" ("student_id", "teacher_id", "memo_target_id", "result", "created_at", "updated_at") VALUES ($1, $2, $3, $4, $5, $6) RETURNING "id" [["student_id", 139], ["teacher_id", 1], ["memo_target_id", 30], ["result", "t"], ["created_at", "2015-09-13 08:08:05.205922"], ["updated_at", "2015-09-13 08:08:05.205922"]]
(0.6ms) COMMIT
Completed 500 Internal Server Error in 6145ms
NoMethodError (undefined method `[]' for nil:NilClass):
app/controllers/memorisation_controller.rb:33:in `block (2 levels) in import'
app/controllers/memorisation_controller.rb:30:in `block in import'
app/controllers/memorisation_controller.rb:29:in `import'
Rendered /Users/Javu/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/actionpack-4.2.0/lib/action_dispatch/middleware/templates/rescues/_source.erb (135.6ms)
Rendered /Users/Javu/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/actionpack-4.2.0/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb (69.8ms)
Rendered /Users/Javu/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/actionpack-4.2.0/lib/action_dispatch/middleware/templates/rescues/_request_and_response.html.erb (13.1ms)
Rendered /Users/Javu/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/actionpack-4.2.0/lib/action_dispatch/middleware/templates/rescues/diagnostics.html.erb within rescues/layout (270.0ms)
Cannot render console with content type multipart/form-dataAllowed content types: [#<Mime::Type:0x007fd4d2cd4c28 @synonyms=["application/xhtml+xml"], @symbol=:html, @string="text/html">, #<Mime::Type:0x007fd4d2cd4868 @synonyms=[], @symbol=:text, @string="text/plain">, #<Mime::Type:0x007fd4d2ccc2a8 @synonyms=[], @symbol=:url_encoded_form, @string="application/x-www-form-urlencoded">]
我用byebug
查看了它,看看导入或第139条记录是否有任何问题,但一切似乎都没问题。
我想知道造成这个问题的原因以及如何纠正它。
答案 0 :(得分:3)
row
为nil
,这就是您收到此错误的原因,请尝试使用以下代码。
def import
require 'csv'
all_targets = MemoTarget.order(:id).includes(:memo_level).map do |t|
{
:id => t.id,
:target => t.target_number,
:level => t.memo_level.level_number
}
end
CSV.foreach(params[:file].path, headers: true) do |row|
next if row.all?(&:blank?)
the_target = MemoTest.create do |test|
test.student_id = row["student_id"]
test.teacher_id = session[:user_id]
test.memo_target_id = all_targets.find {|t| t[:level] == row["memo_level"].to_i and t[:target] == row["memo_target"].to_i}[:id]
test.result = true
end
end
redirect_to '/memorisation', notice: 'Student memorisation current targets imported'
end