如何将Date.new的记录范围限制为每个月的几个星期？6

Question

为了澄清，我正在构建一个包含三个参数的搜索，即月/年/周数。我需要知道如何根据传递的周数返回记录。例如，最有可能有5个星期。当我选择所有三个参数时，我应该得到7天或更短时间的记录。目前，我已经成功地按月/年检索了记录，但现在我将星期数作为参数引入。如何将周号传递给date.new对象？

index.html.erb

  <%= form_tag amb_chart_records_path, :method => :get, :class => "ui form" %>
    <div class="three fields">
     <div class="field">
      <%= select_month(@month.present? @month : nil, {:include_blank => "Select Month"...%>
    </div>
    <div class="field">
        <%= select_year(@year.present? ? @year : Date.today, {:include_blank => "Select Year"..%>
    </div>
    <div class="field">
      <%= select_tag :week, options_for_select([["Week 1", 1], ["Week 2", 2], ["Week 3", 3], ["Week 4", 4], ["Week 5", 5]], params[:week]), class: 'ui dropdown' %>
    </div>    
    </div>
  <div class="field text-center">
    <%= submit_tag("Search", :id => "button", :class => "ui button basic green" %>
  </div>
    <% end %>

amb_chart_records_controller.rb

def index
  if params[:commit] == "Previous" || params[:commit] == "Next"
    now = Date.new(params[:current_year].to_i, params[:current_month].to_i)
    if params[:commit] == "Previous"
      target_date = now - 1.month
    else
      target_date = now + 1.month
    end
  elsif params.has_key?(:select)
    target_date = Date.new(params[:select][:year].to_i, params[:select][:month].to_i, 1)
    week_numb = params[:select][:week].to_i
  else
    target_date = Date.new(Date.today.year, Date.today.month, 1)
    week_numb = 1
  end
  @year = target_date.year.to_i
  @month = target_date.month.to_i
  @week_numb = target_date.cweek.to_i
  @facilities = Facility.where(is_ambulatory_chart_enabled: true)
  @ambulatory_chart_records = @facilities.includes(:amb_chart_records).order(record_date: :desc).where(:record_date => target_date..target_date + 1.month)
end

def week(year, month, week_number)
  Date.new(year, month, 7 * week_number - 6)
end

Answer 1

要在Ruby中获得一周的开始，请使用Date#commercial方法：

irb(main):019:0> Date.commercial(2020, 25, 1)
=> Mon, 15 Jun 2020

这假设每周从星期一开始。如果您需要从周日开始的ISO周，只需用#改变将日期更改一天即可。

irb(main):020:0> Date.commercial(2020, 25, 1).change(day: -1)
=> Tue, 30 Jun 2020

如果要根据周数进行查询，一种方法是在开始日期和结束日期之间传递一个范围：

w_start = Date.commercial(year, week_number, 1)
w_end = Date.commercial(year, week_number, 7)
Model.where(some_column: w_start..w_end)

作为一种较少的多角化解决方案，您还可以使用数据库中的日期函数从日期列中提取星期数：

# Postgres
User.where('EXTRACT(week from created_at)::int = ?', 26)
    .where('EXTRACT(year from created_at)::int = ?', 2020)

# MySQL
User.where('WEEK(created_at) = ?', 26)
    .where('YEAR(created_at) = ?', 2020)

如果您使用的是基于周的分组或聚合，则这更有用。