Issue creating dynamic params

Question

I did an app using rails with ranges of times and I'm trying to create a dynamic params to not repeat all my times for every year, I just want to select the year and the query from my controller with do all.

Here is my table:

|policies|
  |id|   |date_ini|   |date_end|
   1     2013-01-01   2014-01-01      
   2     2012-02-01   2013-02-01     
   3     2013-03-01   2013-03-03     
   4     2013-04-01   2013-08-01     

Here is the range:

 date_ini <=    range_of_each_policy    <= date_end

Here is the logic using year 2013:

|jan| |feb| |mar| |apr| |may| |jun| |jul| |ago| |sep| |oct| |nov| |dic|
 id1   id1   id1   id1   id1   id1   id1   id1   id1   id1   id1   id1
 id2   id2   __________________________________________________________
 __________  id3 ______________________________________________________
 _______________   id4   id4   id4   id4   id4  _______________________ 

Also it will show per month:

 jan  feb   mar  apr.........sep oct nov dec
  2    2     2    2....       1   1   1   1

This is a query for the sum it is working using mysql:

SET @year := 2013;

SELECT
  SUM(CONCAT(@year, '-01-01') BETWEEN date_ini AND date_end) Jan,
  SUM(CONCAT(@year, '-02-01') BETWEEN date_ini AND date_end) Feb,
  SUM(CONCAT(@year, '-03-01') BETWEEN date_ini AND date_end) Mar,
  SUM(CONCAT(@year, '-04-01') BETWEEN date_ini AND date_end) Apr,
  SUM(CONCAT(@year, '-05-01') BETWEEN date_ini AND date_end) May,
  SUM(CONCAT(@year, '-06-01') BETWEEN date_ini AND date_end) Jun,
  SUM(CONCAT(@year, '-07-01') BETWEEN date_ini AND date_end) Jul,
  SUM(CONCAT(@year, '-08-01') BETWEEN date_ini AND date_end) Aug,
  SUM(CONCAT(@year, '-09-01') BETWEEN date_ini AND date_end) Sep,
  SUM(CONCAT(@year, '-10-01') BETWEEN date_ini AND date_end) Oct,
  SUM(CONCAT(@year, '-11-01') BETWEEN date_ini AND date_end) Nov,
  SUM(CONCAT(@year, '-12-01') BETWEEN date_ini AND date_end) `Dec`
FROM
  policies
WHERE
  date_end >= CONCAT(@year, '-01-01')
  AND 
  date_ini <= CONCAT(@year, '-12-01')

Here is the link http://sqlfiddle.com/#!2/dfcd5/2

Here is my controller:

  @year= params[:year]

  @var =Policy.find_by_sql("SELECT
  SUM(CONCAT(@year, '-01-01') BETWEEN date_ini AND date_end) as jan,
  SUM(CONCAT(@year, '-02-01') BETWEEN date_ini AND date_end) as feb,
  SUM(CONCAT(@year, '-03-01') BETWEEN date_ini AND date_end) as mar,
  SUM(CONCAT(@year, '-04-01') BETWEEN date_ini AND date_end) as apr,
  SUM(CONCAT(@year, '-05-01') BETWEEN date_ini AND date_end) as may,
  SUM(CONCAT(@year, '-06-01') BETWEEN date_ini AND date_end) as jun,
  SUM(CONCAT(@year, '-07-01') BETWEEN date_ini AND date_end) as jul,
  SUM(CONCAT(@year, '-08-01') BETWEEN date_ini AND date_end) as aug,
  SUM(CONCAT(@year, '-09-01') BETWEEN date_ini AND date_end) as sep,
  SUM(CONCAT(@year, '-10-01') BETWEEN date_ini AND date_end) as oct,
  SUM(CONCAT(@year, '-11-01') BETWEEN date_ini AND date_end) as nov,
  SUM(CONCAT(@year, '-12-01') BETWEEN date_ini AND date_end) as `dec`
FROM
  policies
WHERE
  date_end >= CONCAT(@year, '-01-01')
  AND 
  date_ini <= CONCAT(@year, '-12-01')  )"

Here is my view:

<% form_tag :controller=>"policy_management/policy",:action=>"generate_statistical_report" do %>
    Select year: 
    <%= select_tag "year",options_for_select([ ["2012",2012],["2013",2013],["2014",2014]],params[:year].to_i) %>
    <%= submit_tag "Buscar", :name => nil %>
<% end %>

<%= @var[0].try(:jan)  %>

Here is my log:

  Policy Load (3.2ms)   SELECT
         SUM(CONCAT(@year, '-01-01') BETWEEN date_ini AND date_expired) as jan,
         SUM(CONCAT(@year, '-12-01') BETWEEN date_ini AND date_expired) `Dec`
        FROM
         policies
        WHERE
         date_expired >= CONCAT(@year, '-01-01')
         AND 
         date_ini <= CONCAT(@year, '-12-01')

My select box from my view is not passing my params @year

Please somebody can help me with this?

I will really appreciate help or ideas.

Answer 1

you need to use string interpolation "#{@year}"