I am a little stuck with getting an sql result into my page. I want to
run a select distinct that returns all of the different sections
available and displays this as a form select. In my controller I have:
def edit
@resource = Resource.find(params[:id])
@sections = Resource.find_by_sql "SELECT DISTINCT
resources.section FROM resources"
end
And then in my view I have:
<% for option in @sections %>
<option value="<%= section.section %>"
<%= '' selected'' if option.section ==
@resource.section %>>
<%= option.section %>
</option>
<% end %>
When I run this I get the following error:
You have a nil object when you didn''t expect it!
You might have expected an instance of Array.
The error occured while evaluating nil.each
>From what I can see I am doing the same as other examples. I have run
the SQL on its own to make sure it returns a result and it does.
Thanks
Jamie
Jamie, I don''t think your find_by_sql is giving you back what you think it is. You may want to look at what is contained in @sections using debug in your view: <%= debug( @sections ) %> I believe you''ll see its an array having a hash as its only member, and that hash has one key, probably something like ''resources.section''. So to get at your list you''ll need something like: @sections[0][''resource.section''] but the debug should make it clear. Jeff On 6/22/06, Jamie D <jam5t3r.lists@gmail.com> wrote:> > I am a little stuck with getting an sql result into my page. I want to > run a select distinct that returns all of the different sections > available and displays this as a form select. In my controller I have: > > def edit > @resource = Resource.find(params[:id]) > @sections = Resource.find_by_sql "SELECT DISTINCT > resources.section FROM resources" > end > > And then in my view I have: > > <% for option in @sections %> > <option value="<%= section.section %>" > <%= '' selected'' if option.section == @resource.section %>> > <%= option.section %> > </option> > <% end %> > > When I run this I get the following error: > > You have a nil object when you didn''t expect it! > You might have expected an instance of Array. > The error occured while evaluating nil.each > > >From what I can see I am doing the same as other examples. I have run > the SQL on its own to make sure it returns a result and it does. > > Thanks > Jamie > _______________________________________________ > Rails mailing list > Rails@lists.rubyonrails.org > http://lists.rubyonrails.org/mailman/listinfo/rails >-------------- next part -------------- An HTML attachment was scrubbed... URL: http://wrath.rubyonrails.org/pipermail/rails/attachments/20060623/7aec4950/attachment.html
Jeff, adding <%= debug( @sections ) %> to the view displays the following: --- Nothing more, I tried <%= debug( @sections[0] ) %> as well which gives me a null error. What does find_by_sql actually return? Thanks Jamie On 22/06/06, Jeff Everett <jaever@gmail.com> wrote:> Jamie, > > I don''t think your find_by_sql is giving you back what you think it is. You > may want to look at what is contained in @sections using debug in your view: > > <%= debug( @sections ) %> > > I believe you''ll see its an array having a hash as its only member, and that > hash has one key, probably something like '' resources.section''. So to get at > your list you''ll need something like: > > @sections[0][''resource.section''] > > but the debug should make it clear. > > Jeff > > > On 6/22/06, Jamie D <jam5t3r.lists@gmail.com> wrote: > > > I am a little stuck with getting an sql result into my page. I want to > run a select distinct that returns all of the different sections > available and displays this as a form select. In my controller I have: > > def edit > @resource = Resource.find(params[:id]) > @sections = Resource.find_by_sql "SELECT DISTINCT > resources.section FROM resources" > end > > And then in my view I have: > > <% for option in @sections %> > <option value="<%= section.section %>" > <%= '' selected'' if option.section == @resource.section %>> > <%= option.section %> > </option> > <% end %> > > When I run this I get the following error: > > You have a nil object when you didn''t expect it! > You might have expected an instance of Array. > The error occured while evaluating nil.each > > >From what I can see I am doing the same as other examples. I have run > the SQL on its own to make sure it returns a result and it does. > > Thanks > Jamie > _______________________________________________ > Rails mailing list > Rails@lists.rubyonrails.org > http://lists.rubyonrails.org/mailman/listinfo/rails > > > _______________________________________________ > Rails mailing list > Rails@lists.rubyonrails.org > http://lists.rubyonrails.org/mailman/listinfo/rails > > >
I was just wondering if I am going about this the correct way. In my database I have a "section" field which contains the section the record is filed under. What I want to do is populate a select form field with a list of available sections, hence the use of select distinct. Would there be a built in function within rails for doing this? Jamie On 22/06/06, Jamie D <jam5t3r.lists@gmail.com> wrote:> Jeff, > > adding <%= debug( @sections ) %> to the view displays the following: > > --- > > Nothing more, I tried <%= debug( @sections[0] ) %> as well which gives > me a null error. > > What does find_by_sql actually return? > > Thanks > Jamie > > > On 22/06/06, Jeff Everett <jaever@gmail.com> wrote: > > Jamie, > > > > I don''t think your find_by_sql is giving you back what you think it is. You > > may want to look at what is contained in @sections using debug in your view: > > > > <%= debug( @sections ) %> > > > > I believe you''ll see its an array having a hash as its only member, and that > > hash has one key, probably something like '' resources.section''. So to get at > > your list you''ll need something like: > > > > @sections[0][''resource.section''] > > > > but the debug should make it clear. > > > > Jeff > > > > > > On 6/22/06, Jamie D <jam5t3r.lists@gmail.com> wrote: > > > > > I am a little stuck with getting an sql result into my page. I want to > > run a select distinct that returns all of the different sections > > available and displays this as a form select. In my controller I have: > > > > def edit > > @resource = Resource.find(params[:id]) > > @sections = Resource.find_by_sql "SELECT DISTINCT > > resources.section FROM resources" > > end > > > > And then in my view I have: > > > > <% for option in @sections %> > > <option value="<%= section.section %>" > > <%= '' selected'' if option.section == @resource.section %>> > > <%= option.section %> > > </option> > > <% end %> > > > > When I run this I get the following error: > > > > You have a nil object when you didn''t expect it! > > You might have expected an instance of Array. > > The error occured while evaluating nil.each > > > > >From what I can see I am doing the same as other examples. I have run > > the SQL on its own to make sure it returns a result and it does. > > > > Thanks > > Jamie > > _______________________________________________ > > Rails mailing list > > Rails@lists.rubyonrails.org > > http://lists.rubyonrails.org/mailman/listinfo/rails > > > > > > _______________________________________________ > > Rails mailing list > > Rails@lists.rubyonrails.org > > http://lists.rubyonrails.org/mailman/listinfo/rails > > > > > > >
On 6/23/06, Jamie D <jam5t3r.lists@gmail.com> wrote:> > I was just wondering if I am going about this the correct way. In my > database I have a "section" field which contains the section the > record is filed under. What I want to do is populate a select form > field with a list of available sections, hence the use of select > distinct. Would there be a built in function within rails for doing > this? > > Jamie > > On 22/06/06, Jamie D <jam5t3r.lists@gmail.com> wrote: > > Jeff, > > > > adding <%= debug( @sections ) %> to the view displays the following: > > > > --- > > > > Nothing more, I tried <%= debug( @sections[0] ) %> as well which gives > > me a null error. > > > > What does find_by_sql actually return? > > > > Thanks > > Jamie > > > > > > On 22/06/06, Jeff Everett <jaever@gmail.com> wrote: > > > Jamie, > > > > > > I don''t think your find_by_sql is giving you back what you think it > is. You > > > may want to look at what is contained in @sections using debug in your > view: > > > > > > <%= debug( @sections ) %> > > > > > > I believe you''ll see its an array having a hash as its only member, > and that > > > hash has one key, probably something like '' resources.section''. So to > get at > > > your list you''ll need something like: > > > > > > @sections[0][''resource.section''] > > > > > > but the debug should make it clear. > > > > > > Jeff > > > > > > > > > On 6/22/06, Jamie D <jam5t3r.lists@gmail.com> wrote: > > > > > > > I am a little stuck with getting an sql result into my page. I want > to > > > run a select distinct that returns all of the different sections > > > available and displays this as a form select. In my controller I have: > > > > > > def edit > > > @resource = Resource.find(params[:id]) > > > @sections = Resource.find_by_sql "SELECT DISTINCT > > > resources.section FROM resources"I don''t know if it will do what you want but you could try the :select option for find. I haven''t used it myself so I don''t know if it will work but I think it goes something like @sections = Resouce.find( :all, :select => "DISTINCT section")> > end > > > > > > And then in my view I have: > > > > > > <% for option in @sections %> > > > <option value="<%= section.section %>" > > > <%= '' selected'' if option.section == @resource.section %>> > > > <%= option.section %> > > > </option> > > > <% end %> > > > > > > When I run this I get the following error: > > > > > > You have a nil object when you didn''t expect it! > > > You might have expected an instance of Array. > > > The error occured while evaluating nil.each > > > > > > >From what I can see I am doing the same as other examples. I have run > > > the SQL on its own to make sure it returns a result and it does. > > > > > > Thanks > > > Jamie > > > _______________________________________________ > > > Rails mailing list > > > Rails@lists.rubyonrails.org > > > http://lists.rubyonrails.org/mailman/listinfo/rails > > > > > > > > > _______________________________________________ > > > Rails mailing list > > > Rails@lists.rubyonrails.org > > > http://lists.rubyonrails.org/mailman/listinfo/rails > > > > > > > > > > > > _______________________________________________ > Rails mailing list > Rails@lists.rubyonrails.org > http://lists.rubyonrails.org/mailman/listinfo/rails >-------------- next part -------------- An HTML attachment was scrubbed... URL: http://wrath.rubyonrails.org/pipermail/rails/attachments/20060623/be89826c/attachment.html
Jamie D wrote:> I was just wondering if I am going about this the correct way. In my > database I have a "section" field which contains the section the > record is filed under. What I want to do is populate a select form > field with a list of available sections, hence the use of select > distinct. Would there be a built in function within rails for doing > this? > > JamieArray has a method ''uniq'': [1,2,1].uniq # [1,2] -- Posted via http://www.ruby-forum.com/.
> def edit > @resource = Resource.find(params[:id]) > @sections = Resource.find_by_sql "SELECT DISTINCT > resources.section FROM resources" > end > > And then in my view I have: > > <% for option in @sections %> > <option value="<%= section.section %>" > <%= '' selected'' if option.section == @resource.section %> > <%= option.section %> > </option> > <% end %> >These errors are tough to track down, but I think rails is getting "confused" with resource names or I should say you are confusing rails. I havent tested but what about trying this: def edit @theresource = Resource.find(params[:id]) @theoptions = Resource.find_by_sql "SELECT DISTINCT resources.section as dsection FROM resources" end <% for theoption in @theoptions %> <option value="<%= theoption.dsection %>" <%= '' selected'' if theoptions.dsection == @theresource.section %> <%= thoption.dsection %> </option> <% end %> -- Posted via http://www.ruby-forum.com/.