Temporarily I'm using <td><%= rolename[0] %> </td> to eliminate brackets and double quotes. But there should be better way to do this. Its an obvious situation where we have to select specific fields of a record which satisfies some condition. All I want is Active Record query equivalent to this SELECT role_name FROM role WHERE role.id = user.roleid
Thank you On Sun, Jul 5, 2015 at 4:20 PM, Padmahas Bn <[email protected]> wrote: > I am trying to retrieve only one field instead of all field. Hence > guides.rubyonrails.org suggest to use Model.select("field_name, > separated_by, comma") here > <http://guides.rubyonrails.org/active_record_querying.html#selecting-specific-fields>. > But the thing is this will produce the SQL *Select field_name FROM Model*. > I want to extend this to include *where* clause. > > Why I want to do this > > This is the code in my index page > > <tbody> > <% @users.each do |user| %> > <% *rolename = Role.where(id: user.roleid).pluck(:role_name)* %> > <tr> > <td><%= user.userid %></td> > <td><%= user.fname %></td> > <td><%= user.lname %></td> > <td><%= user.email %></td> > <td><%= user.phno %></td> > <td><%= rolename %></td> > <td><%= link_to 'Show', user ,:class => 'btn btn-default' %></td> > <td><%= link_to 'Edit', edit_user_path(user),:class => 'btn btn-default' > %></td> > <td><%= link_to 'Delete', user, method: :delete, data: { confirm: 'Are you > sure?' } ,:style => 'color:#FFFFFF', :class => 'btn btn-danger'%></td> > </tr> > <% end %> > </tbody> > > The large font code after loop is giving the result what I want but the > result is enclosed with big brackets and double quotes like this [" > result"]. Because that code will return an array of values. > > So I found I have to use Model.select to retrieve single object. Then I > tried *<% rolename = Role.select("role_name").where(id: user.roleid) %> *but > its returning some invalid value like 00x30000658487. > Again I tried with this *<% rolename = Role.find_by_sql("SELECT role_name > FROM ROLES, USERS WHERE roles.id <http://roles.id> = users.roleid.to_i") > %>, *its giving error *PG::UndefinedTable: ERROR: missing FROM-clause > entry for table "roleid"* > By comparing all types of queries I thought it is good to include where > clause along with Model.select. But couldn't find anywhere. > > Please help me > > Thank you > > -- > You received this message because you are subscribed to the Google Groups > "Ruby on Rails: Talk" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/rubyonrails-talk/5d915337-b273-49b5-a93d-1583679be8fc%40googlegroups.com > <https://groups.google.com/d/msgid/rubyonrails-talk/5d915337-b273-49b5-a93d-1583679be8fc%40googlegroups.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-talk/CAC_h78KBL92H31pq537onA%2B5DfOtWWugMiefNnSws7x_fNXkQg%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
