使用 gsub 用换行符替换特定字符（Ruby、Rails 控制台）
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Using gsub to replace a particular character with a newline (Ruby, Rails console)
提问by pakeha
Annoying problem. I am trying to replace all semicolon characters in my Model's description field with newline characters (\n). The database is sqlite. The field is of type text.
烦人的问题。我试图用换行符 (\n) 替换模型描述字段中的所有分号字符。数据库是sqlite。该字段是文本类型。
If I do it manually at the rails console (manually typing the description for a single record using \n for line breaks), the rails console automatically escapes the \n, and the description field becomes filled with \\n.
如果我在 rails 控制台上手动执行此操作（使用 \n 为换行符手动键入单个记录的描述），rails 控制台会自动转义 \n，并且描述字段将填充为\\n。
If I do it programmatically using gsub, I get the following situation:
如果我使用 gsub 以编程方式执行此操作，则会出现以下情况：
>> s = Sample.find(:first)
=> ...details of record ...
=> ...记录详情...
>> s.description.gsub!(/;/,"\n")
=> ...success - it all looks good, new lines in the returned value are represented by \n...
=> ...成功 - 一切看起来都不错，返回值中的新行由 \n... 表示
>> s.save
=> true
>> reload!
Reloading
=> true
>> s = Sample.find(:first)
=> ...details of record ...
=> ...记录详情...
>> s.description
=> ... the description field still has semicolons in it rather than newline characters ...
=> ...描述字段中仍然有分号而不是换行符...
AHHHHHH!!!!!!!
啊啊啊啊啊！！！！！！
回答by Vincent Robert
s.descriptionreturns a copy of the description so gsub!will only modify the copy and return the modified copy.
s.description返回描述的副本，因此gsub!只会修改副本并返回修改后的副本。
Try this:
尝试这个：
s.description = s.description.gsub(/;/,"\n")
回答by cldwalker
If you're editing ActiveRecord fields a lot, you can just edit them in your editor with the rails plugin console_update
如果你经常编辑 ActiveRecord 字段，你可以在你的编辑器中使用 rails 插件console_update编辑它们
