如果每条记录为零，Rails 会更新多条记录

Question

I want to update record in one, single shot to db when published_at is nil instead of two:

  portfolio_report.update!(published: true)
  portfolio_report.update!(published_at: DateTime.current) if portfolio_report.published_at.nil?

Is it possible to have something like:

  portfolio_report.update!(
    published: true,
    published_at: DateTime.current if nil?
  )

Answer 1

You have a couple of options here actually. Maybe the one that answers your question most directly is:

portfolio_report.update!(
  published: true,
  published_at: portfolio_report.published_at || DateTime.current
)

(This assumes published_at has not been updated from another thread and made this in-memory instance stale, but it matches the behaviour of the original example, so I assume that is not a problem.)

You could also accomplish the same thing with a before_update callback, but that would both be more indirect and require more code.

Either way, it's probably a good idea to encapsulate this in a method on your PortfolioReport model:

class PortfolioReport < ApplicationRecord
  def publish!
    update!(
      published: true,
      published_at: published_at || DateTime.current
    )
  end
end

This way every call site does not need to remember to get this right.

Answer 2

You can use where to limit it and make one line.

portfolio_report.where(published_at: nil).update!(published_at: DateTime.current, published: true)

Answer 3

You can add data to record and after save it.

portfolio_report.published = true
portfolio_report.published_at = DateTime.current if portfolio_report.published_at.nil?
portfolio_report.save!