[Ruby On Rails] How to retrieve and display column information of multiple records linked to a specific id at once
Premise
Suppose you have a table like this.
hoges table
| id | text | content_id |
|---|---|---|
| 1 | morning | 1 |
| 2 | afternoon | 2 |
| 3 | evening | 2 |
| 4 | night | 3 |
| 5 | midnight | 3 |
| 6 | late night | 3 |
Way of thinking
To retrieve the column information of multiple records associated with a specific id at once, you can display multiple data information by using the each method in the form of "instance variable.each" in the view.
How to write
- To use each method, you must pass an array. By using the where method, the objects that match the conditions are fetched as an array. In this case, specify Hoge (hoges table) and use the where method to assign to @hoges the id that matches the content_id carried by params.
hoges_controller.rb
def show
@hoges = Hoge.where(content_id: params[:id])
end
- As mentioned in the concept, multiple information can be displayed by using the each method. For example, the description is as follows.
ruby:show.html.erb
<% @hoges.each do |hoge| %>
<%= hoge.text %>
<% end %>
Display image
If you write the above, you will see the following display.
If content_id "1" is included in params
If content_id "2" is included in params
If content_id "3" is included in params
Reference article
https://qiita.com/tanaka7014/items/f1c4b6505a2c672ea1f7
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