如何覆盖 Rails 模型中的列? [英] How to override a column in Rails model?

问题描述

我有一个数据库表的模型.我想覆盖该特定表的列名.我将如何实现它.

I have a model for one of my database tables. I want to override the column name for that particular table. How would I achieve it.

例如，让我的表名为 DUMMY，它有一列名为 col_a

For example, let my table be called DUMMY and it has one column called col_a

col_a
20
34
42
23
12

我会做一个@dummy.col_a.现在，对于以 0 结尾的数字，此方法应该返回 0，对于其他所有内容，它应该返回原始值.我可以通过定义一个新方法来做到这一点，但我想覆盖列名本身.请帮忙.

I would be doing a @dummy.col_a. Now this method should return me 0 for numbers ending with 0 and for everything else, it should return the original value. I could do that by defining a new method, but I want to override the column name itself. Please help.

推荐答案

您可以覆盖 col_a 方法.使用 read_attribute 方法读取数据库中的值.像这样:

You can override the col_a method. Use the read_attribute method to read the value in database. Something like this:

def col_a
  if self.read_attribute(:col_a).to_s.end_with?('0')
    0
  else
    self.read_attribute(:col_a)
  end
end

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