undefined method `friend_id' for #<ActiveRecord::Relation:0x007fc4b54935f0> - ruby-on-rails

Question

Now I am trying to set up switching button to follow someone.
<div class="onoff">
<% unless session[:user_id] == member.id %>
<% if #isFr.friend_id == member.id %>
<%= link_to'off', {:controller => 'members', :action => 'index', :id =>
member.id}, class: "btn btn-midium btn-primary"%><br/>
※following
<% else %>
<%= link_to'on', {:controller => 'members', :action => 'index', :id =>
member.id}, class: "btn btn-midium btn-primary"%><br/>
※not following
<% end %>
<% end %>
</div-->
But I got an error message.
undefined method `friend_id' for #<ActiveRecord::Relation:0x007fc4b54935f0>
and looked into #isFr and it has
>> #isFr
=> [#<Friend id: 196, member_id: 2, friend_id: 3, created_at: "2013-12-23 01:28:18", updated_at: "2013-12-23 01:28:18">]
So, I can't extract friend_id value from #isFr.
How can I solve this?
☆members_controller
def index
if !checklogin? then return end
#members = Member.where("id >=1").order("created_at desc").paginate(:page => params[:page], :per_page => 10).scoped
if Friend.where(:member_id => session[:user_id], :friend_id => params[:id]).exists? then
Friend.where(:member_id => session[:user_id], :friend_id => params[:id]).each do |f|
f.destroy
end
else
Friend.new({:member_id => session[:user_id], :friend_id =>params[:id].to_i}).save
end
#isFr =Friend.where(:member_id => session[:user_id], :friend_id => #members.map(&:id)).limit(1)
respond_to do |format|
format.html # index.html.erb
format.json
end
end
☆index.html.erb(members#index)
<table class="table">
<tr>
<th>写真</th>
<th>名前</th>
<th>分野</th>
<th>場所</th>
<th>経験</th>
<th></th>
<%# if Member.find(session[:user_id]).admin %>
<%# end %>
</tr>
<% #members.each do |member| %>
<tr>
<td>
<% if member.provider %>
<%=image_tag member.image ,:size=>'30x30'%>
<% elsif member.avatar_file_name %>
<%= image_tag member.avatar.url(:thumb), :width =>'30px', :height =>'30px' %>
<% else %>
<%= image_tag "love.png", :size=>'30x30' %>
<% end %>
</td>
<td>
<%= member.name %>
<% if member.provider == "facebook" %>
<a target="_blank" href="http://www.facebook.com/<%=member.uid %>"> <%=image_tag "fb.png" ,:size=>'20x20'%> </a>
<% elsif member.provider == "twitter" %>
<a target="_blank" href="http://www.twitter.com/<%=member.name %>"> <%=image_tag "twitter.png" ,:size=>'20x20'%> </a>
<% end %>
</td>
<td><%= member.field %></td>
<td>
<% if member.url.present? %>
<%=link_to member.place ,member.url ,:target=>["_blank"] %>
<% else %>
<%= member.place %>
<% end %>
</td>
<td><%= member.experience %></td>
<td>
<div class="onoff">
<% unless session[:user_id] == member.id %>
<% if #isFr.friend_id == member.id %>
<%= link_to'off', {:controller => 'members', :action => 'index', :id =>
member.id}, class: "btn btn-midium btn-primary"%><br/>
※following
<% else %>
<%= link_to'on', {:controller => 'members', :action => 'index', :id =>
member.id}, class: "btn btn-midium btn-primary"%><br/>
※not following
<% end %>
<% end %>
</div-->
<%#= member.friends.count %>
</td>
<% if Member.find(session[:user_id]).admin %>
<td><%= link_to 'Destroy', member, method: :delete, data: { confirm: 'Are you sure?' } %></td>
<% end %>
</tr>
<% end %>
</table>

Answer 1

The problem is at this line
#isFr =Friend.where(:member_id => session[:user_id], :friend_id => #members.map(&:id)).limit(1)
That will respond a ActiveRecord::Relation but you need a Friend object. Try this
#isFr =Friend.where(:member_id => session[:user_id], :friend_id => #members.map(&:id)).first