Need guidance in fetching data using each

[Deepak Sharma]

In my app I have 3 tables Patient, Department and Consultant. In
patient table I have passed foreign key of other other two tables.
Now, In my index view of patient I'm able to fetch data of department
table with each loop :

<tbody>
<% @departments.each do |d| %>
<% @patient = Patient.where(department_id: d.id) %>
<% @patient.each do |patient| %>
<tr>
<td><%= patient.patient_name %></td>
<td><%= patient.patient_age %></td>
<td><%= d.name %></td>
<% end %>
<% end %>
</tbody>

Now my question how should I fetch data from consultant table using
each loop, same way as I did for department table in above code. I
need little guidance on this. Thanks in advance.

--
Cheers!

Deepak Kumar Sharma
Guru Nanak Dev Engineering College
India!

Blog: http://deekysharma.wordpress.com

[Colin Law]

On 5 November 2015 at 09:39, Deepak Sharma <deeky....@gmail.com> wrote:
> In my app I have 3 tables Patient, Department and Consultant. In
> patient table I have passed foreign key of other other two tables.
> Now, In my index view of patient I'm able to fetch data of department
> table with each loop :
>
> <tbody>
> <% @departments.each do |d| %>
> <% @patient = Patient.where(department_id: d.id) %>
> <% @patient.each do |patient| %>

You should not be using Patient.where here, rails will do this for you
if you setup the associations correctly. It should be something like

<% @departments.each do |d| %>

<% d.patients.each do |patient| %>
Such is the magic of Rails.

That assumes you have setup department has_many patients and patient
belongs_to department of course.

>
> Now my question how should I fetch data from consultant table using
> each loop, same way as I did for department table in above code. I
> need little guidance on this. Thanks in advance.

You will need to give a little more information on what you want to
show for us to answer the question.

Colin

[Deepak Sharma]

On Thu, Nov 5, 2015 at 3:41 PM, Colin Law <cla...@gmail.com> wrote:
> You should not be using Patient.where here, rails will do this for you
> if you setup the associations correctly. It should be something like
>   <% @departments.each do |d| %>
>     <% d.patients.each do |patient| %>
> Such is the magic of Rails.

+1

> That assumes you have setup department has_many patients and patient
> belongs_to department of course.

Wow! It works :). Learned something new. Thanks colin for this.

> You will need to give a little more information on what you want to
> show for us to answer the question.

  <tbody>
    <% @departments.each do |d| %>

      <% d.patients.each do |patient| %>

        <tr>
          <td><%= patient.patient_name %></td>

          <td><%= d.name %></td>
          <td><%= patient.consultant %></td>

      <% end %>
    <% end %>
  </tbody>

As shown in above code by using each loop in department I'm able to fetch department table's data in " <td><%= d.name %></td> ". Now I want to fetch same for consultant table i.e fetching consultant data in patient index file.

Rough example :

  <tbody>
    <% @departments.each do |d| %>

      <% d.patients.each do |patient| %>

        <tr>
          <td><%= patient.patient_name %></td>

          <td><%= d.name %></td>
            <% @consultants.each do |c| %>
              <td><%= c.name %></td>
            <% end %>
        </tr>

      <% end %>
    <% end %> 
  </tbody>

Something like above which fetch name field from consultant table in patient's index file according to their respective ID.

[Colin Law]

On 5 November 2015 at 10:32, Deepak Sharma <deeky....@gmail.com> wrote:
> ...

> Now I want to fetch
> same for consultant table i.e fetching consultant data in patient index
> file.
>
> Rough example :
>
> <tbody>
> <% @departments.each do |d| %>
> <% d.patients.each do |patient| %>
> <tr>
> <td><%= patient.patient_name %></td>
> <td><%= d.name %></td>
> <% @consultants.each do |c| %>
> <td><%= c.name %></td>
> <% end %>
> </tr>
> <% end %>
> <% end %>
> </tbody>
>
> Something like above which fetch name field from consultant table in
> patient's index file according to their respective ID.

What is the relationship between consultants and patients, that is in
terms of has_many, belongs_to etc?

Colin

[Deepak Sharma]

On Thu, Nov 5, 2015 at 4:15 PM, Colin Law <cla...@gmail.com> wrote:
>
> What is the relationship between consultants and patients, that is in
> terms of has_many, belongs_to etc?

# Patient

[Deepak Sharma]

# Patient

class Patient < ActiveRecord::Base
belongs_to :department
belongs_to :consultant
end

# Consultant

class Consultant < ActiveRecord::Base
has_many :patients
end

# Department

class Department < ActiveRecord::Base
has_many :patients
end

[Colin Law]

So there is only one consultant for a patient. Assuming that is the
information you want then something like

<% @departments.each do |d| %>
<% d.patients.each do |patient| %>
<tr>
<td><%= patient.patient_name %></td>
<td><%= d.name %></td>

<td><%= patient.consultant.name %></td>

I am a little surprised that this is not already clear to you. I
assume that you have worked right through railstutorial.org as I have
suggested to you several times previously. Have you done that? If
not then please do so, it will save you from getting stuck on simple
issues and having to waste both your time asking such questions and my
time answering them.

Cheers

Colin