How to loop through the array obtained from the database and change one of the fields

Question

I receive from the database the entire list.

#<ActiveRecord::Relation [#<Item id: 1, name: "AAA", unit_price: 10000><#Item ....]

Next, I need to go through a loop or an iterator and divide the value of unit_price by 100, write the result back and display it in view.

I try this:

 def index @items = Item.all @items.each{ @items[unit_price] = @items[unit_price] /100 } end

In response, I get:

undefined local variable or method `unit_price '

I look in manual hashes

 user = {name:"Vasya", last_name: "Petrov", age: 20} user[:name] #=> "Vasya"

and try this:

 def index @items = Item.all @items.each{ @items[:unit_price] = @items[:unit_price] /100 } end

getting an answer

no implicit conversion of Symbol into Integer

Probably the value of @items [: unit_price], it does not consider the integer, although in the database it is ok ...

  def index @items = Item.all @items.each{ @items[:unit_price] = @items[:unit_price].to_i /100 } end

getting an answer

no implicit conversion of Symbol into Integer

So @ items.unit_price also tried, there is no such method unit_price

How to sort through these arrays and how to access the necessary fields?

you have the price in whole units of 456, and you want to display them in the form of 4.46?
In particular, you do not understand how each works, you would at least read the language site .

Accepted Answer · 2017-02-27T21:18:55

You do not need to change the values in the collection. You need to use the correct helper and partial when output. Create a partial (_item.html.erb) to display one element and use something like a helper :

 <%= number_to_currency(item.unit_price / 100.0) %>

But mostly view

 <%= render @items %>

The best option would be to use gem draper or keynote

Answer 2 · 2017-02-27T20:51:37

Need to go through the skin element

 def index @items = Item.all @items.each do |item| item[:unit_price] /= 100 item.save # + сохранение в бд end end

Updated the answer !!

I need to get the same output as @items but the unit_price field: 10,000 should eventually take the form 100.00

How to loop through the array obtained from the database and change one of the fields

2 answers 2

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