从 Rails 6 中的 Postgres db 解析时间字段以检索小时和分钟？

Question

I have a model Open times for shops. The open times tables comprises a field as below. I would like to query the opening and closing times like: 08:00 - 17:00

t.time "closes"

the view helpers is the following: <%= display_day(0) %>. where 0 is sunday

I get to the following array with pluck.

=> [Sat, 01 Jan 2000 08:00:00 UTC +00:00]

I would like to ignore the date component and only show Hours and Minutes.

Thanks to tadman and Caleb, we could get to the following:

def display_day(value)
  is_open = @company.opentimes.where(day: value, openpublic: true)
  if is_open.pluck(:openpublic) == false
    'closed'
  else
    start = is_open.pluck(:opens)
    close = is_open.pluck(:closes)
    if start.nil?
      'no data'
    else
      DateTime.parse(start[0].to_s).strftime('%H.%M')
      DateTime.parse(close[0].to_s).strftime('%H.%M')
    end
  end
end

I will clean the code and post it there. in the meantime, if you have any suggestions, feel free to suggest.

Answer 1

You should be able to use both the DateTime parse and strftime methods to format the time however you want.

Based on the plucking you're doing:

start = @company.opentimes.where(day: value).pluck(:opens)
=> [Sat, 01 Jan 2000 08:00:00 UTC +00:00]

DateTime.parse(start[0].to_s).strftime('%H:%M')
=> "08:00"

You could create a little formatting helper like:

def format_time(time)
  DateTime.parse(time.to_s).strftime('%H.%M')
end

And then use this to return the final string like: 08.00 - 17.00 :

def hours_open(day)
  opentime = @company.opentimes.where(day: day, openpublic: true).first

  if opentime.opens && opentime.closes
    "#{format_time opentime.opens} - #{format_time opentime.closes}"
  elsif !opentime
    'closed'
  else
    'no data'
  end
end

Answer 2

Why don't you use the strftime method?

Time.now.strftime('%T')    # this will output something like "15:26:54"
Time.now.strftime('%H:%M') # this will output something like "15:26"