Group and count in Rails - sql

I have this bit of code and I get an empty object.
#results = PollRoles.find(
:all,
:select => 'option_id, count(*) count',
:group => 'option_id',
:conditions => ["poll_id = ?", #poll.id])
Is this the correct way of writing the query? I want a collection of records that have an option id and the number of times that option id is found in the PollRoles model.
EDIT: This is how I''m iterating through the results:
<% #results.each do |result| %>
<% #option = Option.find_by_id(result.option_id) %>
<%= #option.question %> <%= result.count %>
<% end %>

What do you get with this:
PollRoles.find(:all,:conditions=>["poll_id = ?",#poll.id]).collect{|p| p.option_id}

You want to use this function to do things like this
PollRoles.count(:all, :group => 'option_id') should return a hash mapping every option_id with the number of records that matched it.

Related

Rails form - search engine

I try to create simple search engine but I meet some problmes. I have several search_field in my form and if either is empty should returns all objects. Otherwise when it has any content it should be selected by that content. Below is my sample form:
<%= form_for :product, url: products_path, method: :get do |form| %>
<%= form.search_field :brand %>
<%= form.search_field :model %>
<%= form.search_field :price_from %>
<%= form.search_field :price_to %>
<%= form.submit 'Submit' %>
<% end %>
my model method:
def self.search(search)
where(brand: search[:brand]).where(model: search[:model]).where("price >= ?", search[:price_from]).where("price <= ?", search[:price_to])
end
But the above piece of code is wrong because if I leave some field empty it is treated directly as empty string instead of ignore this field and final result is not correct.
Summary this form should work similarly to filter on online store
You'd could do something like this
def self.search(search)
results = all
results = results.where(brand: search[:brand]) if search[:brand]
results = results.where(model: search[:model]) if search[:model]
results = results.where("price >= ?", search[:price_from]) if search[:price_from]
results = results.where("price <= ?", search[:price_to]) if search[:price_to]
return results
end
Good luck.

Rails SQL Where If condition

I am trying to create an advanced search form for a rails blog
I'm trying to avoid using a gem
I have a table posts with a title, location_id and category_id, the last two are connected to two tables Location (:small, :greater) and Category (name), but I doubt that's important for this question
I have a search form which finds all posts where location_id and category_id is equal to the user set option
<%= form_for(#advanced_search) do |f| %>
<div class="field">
<%= f.label :category_search %><br>
<%= f.collection_select :category_search, Category.all, :id, :name, :
include_blank => "any category" %>
</div>
<div class="field">
<%= f.label :location_search %><br>
<%= f.collection_select :location_search, Location.all, :id, :locationsmallgreat
,:include_blank => "any city" %>
<%= f.submit %>
<% end %>
Once again i doubt that's important for the question which is probably simpler than I'm explaining it to be
Basically I have this so far
#posts = Post.all
#posts = #posts.where('category_id = ?', #advanced_search.category_search) if #advanced_search.category_search != "any category"
#posts = #posts.where('location_id = ?', #advanced_search.location_search) if #advanced_search.location_search != "any city"
But it doesn't seem to work
I need it to work as so, If the form has Category = Any category (:included_blank => "any category)
and Location = London
It would search for all Posts where location is == london, BUT it would remove the .where for the category, seeing that it is == any city and vice versa if a Category was selected and Location was left blank (:included_blank => "any city)
Thanks
if #advanced_search.category_search.present? && #advanced_search.location_search.present?
Post.
where('category_id = ?', #advanced_search.category_search).
where('location_id = ?', #advanced_search.location_search).
all
elsif #advanced_search.category_search.present?
Post.
where('category_id = ?', #advanced_search.category_search).
all
elsif #advanced_search.location_search.present?
Post.
where('location_id = ?', #advanced_search.location_search).
all
else
Post.all
end

Advanced Rails ActiveRecord query using scope

I've been trying for a while to find the best way of querying for the desired result, but I always end up failing at some poing in the query.
Simplified database structure:
User:
id (integer)
first_name (string)
last_name (string)
CourseType:
title (string)
slug (string)
Course:
belongs_to :user
belongs_to :course_type
week (integer)
sold (float)
My controller is calling a scope:
#users = User.sales_results(week)
And here's the scope in my model:
scope :sales_results, lambda { |week|
joins(:courses => [:course_type])
.select("
users.id, users.first_name, users.last_name,
SUM(courses.sold) as total_sold,
COUNT(courses) as num_classes
")
.where("courses.week = ?", week)
.group('users.id')
}
This works fine, and I can use it in my template to show the total amount sold. Although I also want to show a second column where the value sold for some specific types of courses are summed up in. Something like this:
<% #users.each do |user| %>
<%= user.total_sold %>
<%= user.total_sold.where("course_types.slug IN ('H', 'S')") # not possible, but similar to what I desire %>
<% end %>
Update
I ended up adding another scope
scope :sales_results_for_types, lambda { |week, types|
sales_results(week).except(:group).where("course_types.slug IN (?)", types)
.group('users.id')
}
Then calling both scopes in my controller
#users = User.sales_results(...)
#users_filtered = User.sales_results_for_types(...)
Lastly iterating both results at the same time
<% #users.zip(#users_filtered).each do |user, filtered| %>
<%= filtered.total_sold %>
<%= user.total_sold %>
Until I figure out something better. Thanks guys for leading me on the right track.
If you are ok with having another query, you can use this
user.joins(courses: :course_type).sum(:sold, group: 'course_types.slug')
which will give you a hash where the keys are the slugs, and the values are the sums.

Rails: two (or more) instances of same collection_select?

I've got a collection_select instance in a form, and I'm wondering if it's possible to have two or more instances in the same form. They'd be built from the same model, and they would save as if they were checkboxes constructed in an Article.all.each loop. To have these work
<%= f.collection_select("article_ids", Article.where(:page => 1), :id, :name) %>
<%= f.collection_select("article_ids", Article.where(:page => 2), :id, :name) %>
<%= f.collection_select("article_ids", Article.where(:page => 3), :id, :name) %>
in the form is pretty much what I'm after. It's essentially a multiple select but spread over a couple of selects. The field already accepts multiple results, but when I save the form as it is above it only records the option from the final select. Any thoughts?
Cheers!
<%= select_tag "article_ids[]",options_from_collection_for_select(Article.all.collect{|i| [i.name,i.id]),:multiple => true %>
When select multiple options in select list just give article_ids[] , it will store all ids in this array then after you write query how you would store in database.
If set the select tag is multiple true then you will select multiple options other wise you get only one selected value.
or just read below link
http://api.rubyonrails.org/?q=collection%20select
If you want to give f.select then you must give like this
<%= f.collection_select :article_id, Article.all, :id , :name %>
I just went with checkboxes to solve this, because it's truly the stuff of nightmares.
<% #articles.each do |a| %>
<%= check_box_tag("doc[article_ids][]", a.id, #doc.articles.include?(a.id), :class => "article_chooser") %> <a id="<%= a.id %>" class="name"><%= a.name %></a><br />
<% end %>

Rails sorting associations with Ransack

first time poster. I am trying to sort a table of users using the Ransack gem and Kaminari for pagination. When I use name, id, etc. sorting works but when I try an association with posts_count, sorting breaks and won't work. Note: in the view, 'u.posts.count' work correctly. I have tried custom scopes in the users model, and creating custom objects for the search params but nothing seems to work. I think I am having trouble either in the default scope or the #search object not having the data. Need help!
Here are some relevant snippets:
models/user.rb
has_many :posts, :dependent => :destroy
models/post.rb
belongs_to :user
default_scope :order => 'post.created_at DESC'
controllers/users_controller.rb
def index
#title = "User Index"
#search = User.search(params[:q]) # Ransack
#total_users = User.all.count
# .per(10) is the per page for pagination (Kaminari).
#users = #search.result.order("updated_at DESC").page(params[:page]).per(10) #This displays the users that are in the search criteria, paginated.
end
views/users/index.html.erb
..
<%= sort_link #search, :posts_count, "No. of Posts" %> #Sort links at column headers
..
<% #users.each do |u| %> #Display everything in the table
<%= u.posts.count %>
<% end %>
You can add a scope to your User model:
def self.with_posts
joins(:posts).group('posts.id').select('users.*, count(posts.id) as posts_count')
end
and use it like this:
#search = User.with_posts.search(params[:q]) # Ransack
then, you can treat posts_count like any other attribute.
I found a solution:
Controller:
def index
sql = "users.*, (select count(posts.id) from posts\
where posts.user_id = users.id) as count"
#search = User.select(sql).search(params[:q])
if params[:q] && params[:q][:s].include?('count')
#users = #search.result.order(params[:q][:s])
else
#users = #search.result
end
.......
end
View:
<th><%= sort_link #search, :count, "posts count" %></th>