update via Hash or Array

Question

I want to update the subject_id field in Period Model .Where the period loop will be inside the Form. SO, when I submit the Form the passing Parameter is coming as an hash, where Key is the Period.id and the Value is subject_id . So, How can I update it.

In my Show.html.erb I has

 <%= form_tag update_institutes_path, method: : put do %> <% @period.each do |cc | %> <%= cc.subject.name %> <%= collection_select('id', cc.id, Subject.all, : id, : name, selected: cc.id, prompt: true) %> <% end %> <%= submit_tag %> <% end %> 

The SHow action I has

 def show @period = Period.all end 

In the Update action I have

 def update @period = params[:id] keys, values = @period.map { |k,v| [k.to_i, v.to_i] }.transpose values.each { |f| Period.all.update_all(:subject_id => f) } end 

where @period = params[:id] give a parameter like

  #Parameters: {"utf8"=>"✓", "authenticity_token"=>"8SNaUIQ6ZwjYOqBX07QYyVJsbuvYTL2TotSqIg0yj98nYXq5XqJ5XRHqlCvl1aw0lLg9vowyDOl3Hhm+hYDaOA==", "id"=>{"1"=>"3", "4"=>"2"}, "commit"=>"Save changes"}

1. where 1 and 4 in the hash is period_id
2. 3 and 2 in the hash is subject_id.

Then I converted the hash to keys and values

1. where keys is period_id
2. values is subject_id.

Then I looped the values and update the Period.

It is updating, but the Problem is only the last value 2 is updated, where every subject_id becomes 2, I don't no what happens to 3(the first value), only the last value is updated. I am just banging my head to solve this problem for two days. I am new to rails, Please be kind. Thanks for the answer in advance.

Answer 1

You say you have a hash where the keys are period_id and the values are subject_id . Assuming your hash name is period_and_subjects , you want to do this:

Period.update(period_and_subjects.keys, period_and_subject.values)

So, if your period_and_subjects hash looks like {1 => 2, 4 => 5} , it would update the period with id 1 with the subject with id 2 and the period with id 4 with the subject with id 5.

Look at the docs for update .