how to write each loop for has_many in rails? - ruby-on-rails

Question

employee has many skills
skill belongs_to employee
Skills table have employee_id(foreign key).
I want to display in view

Answer 1

There are 4 ways to get the collections of users.
#employees = Employee.all.joins(:skills)
#employees = Employee.all.includes(:skills)
#employees = Employee.all.eager_load(:skills)
In your view add below code in HTML/HAML/SLIM file.
<% #employees.each do |employee| %>
<tr>
<td><%= employee.name %></td>
<td><%= employee.skills.map(&:title).join(", ") %></td>
</tr>
<% end %>`

Answer 2

You could try with something like this.
In controller return all the employees
so it will be like
#employees = Employee.all.includes(:skills)
and in the view you can do
<% #employees.each do |employee| %>
<tr>
<td><%= employee.name %></td>
<td><%= employee.skills.collect(&:title).join(", ") %></td>
</tr>
<% end %>

Answer 3

Best practice in this case is to write an instance method on your Employee class:
class Employee < ApplicationRecord
has_many :skills
def skills_list
skills.pluck(:title).join(', ')
end
end
And use it like this in your view:
<table>
<tr>
<td><%= #employee.id %></td>
<td><%= #employee.name %></td>
<td><%= #employee.skills_list %></td>
<tr>
</table>

Answer 4

You can use:
<table>
<tr>
<th>Employee </th>
<th>Skills</th>
</tr>
<% #employees.each do |employee|%>
<tr>
<td><%= employee.name %></td>
<td><%= employee.skills.map(&:name).join(', ') %></td>
</tr>
<% end %>
</table>
This above code will list all skill names of each employee.
You can read a complete guide here