I have two tables: App (with a release_id field) and User.
Models
class App < ActiveRecord::Base
has_one :user
end
class User < ActiveRecord::Base
belongs_to :app
end
Class
class Stats::AppOverview
def initialize(from:, apps:)
#from = from || Date.new(2010)
#apps = apps
end
def total_count
{ apps: { total: total_app, with_user: app_with_user } }
end
private
def app_since
#apps.where('created_at >= ?', #from)
end
def total_app
devices_since.count
end
def app_with_user
User.where(app: app_since).count
end
end
I would like to return
the number of app records for a given array of release_id
the number of app records that belong to each user, satisfying other criteria
This is how I use the class
Stats::AppOverview.new(from: 1.month.ago.iso8601,
apps: App.where(release_id: [1,2,3,4,5,19,235]).total_count
#=> { apps: { total: 65, with_user: 42 } }
For the moment I do it in two queries, but is it possible to put them in the same query? Is this possible using active record?
Related
How to get the queried data having polymorphic association
I have an 3 models
class Picture < ApplicationRecord
belongs_to :imageable, polymorphic: true
end
class Employee < ApplicationRecord
has_many :pictures, as: :imageable
end
class Product < ApplicationRecord
has_many :pictures, as: :imageable
end```
Employee and Product have column **is_active**.
In rails admin dropdown. I want to display the data where employee and product is **is_active = true.**
Have tried multiple ways to achieve this.
Please let me know if there is any solution?
You can write a custom scope in picture model as below
scope :list_active(imageable_type), -> {
where(imageable_type: imageable_type)
.joins("INNER JOIN #{imageable_type.pluralize} ON
{#imageable_type.pluralize}.id = imageable_id AND
imageable_type = '#{imageable_type}'")
.where('#{imageable_type.pluralize}.is_active = ?', true)
}
Then you can simply list and use the response.
E.g result = []
result << Image.list_active('Employee')
result << Image.list_active('Product')
Every day I need to send letters to users with today's tasks.
For do this I need to find all users who are allowed to send letters, and among these users to find all cards that have a deadline today. The result is three array elements with a nil value. How is this better done and right?
#users = User.all {|a| a.receive_emails true}
#user_cards = []
#users.each_with_index do |user, index|
#user_cards[index] = user.cards.where(start_date: Date.today).find_each do |card|
#user_cards[index] = card
end
end
My user model:
class Card < ApplicationRecord
belongs_to :user
# also has t.date "start_date"
end
My card model:
class User < ApplicationRecord
has_many :cards, dependent: :destroy
# also has t.boolean "receive_emails", default: false
end
Something like #cards_to_send = Card.joins(:users).where("users.receive_emails = true").where(start_date: Date.today)
Have a look at https://guides.rubyonrails.org/active_record_querying.html#specifying-conditions-on-the-joined-tables for the docs on how to query on a joined table.
You could do this with a SQL join like this
User.joins(:cards).where(receive_emails: true, cards: { start_date: Date.today })
https://guides.rubyonrails.org/active_record_querying.html#joining-tables
I have a Product class that has_many Gender through Connection class instances. I want to query to find products that have both end_a and end_b present. The current class method works with 2 caveats:
Fails to return correctly if searching where end_a and end_b are the same. Instead should search if product has 2 instances, not just one of object.
Returns an Array when I want an ActiveRecord_Relation.
The class method .query is below, any feedback or ideas are appreciated.
class Product < ActiveRecord::Base
has_many :connections, dependent: :destroy, as: :connectionable
has_many :genders, through: :connections
def self.query(end_a, end_b)
search_base = active.joins(:connections)
end_a_search = search_base.where(connections: { gender_id: end_a } )
end_a_search & search_base.where(connections: { gender_id: end_b } )
end
end
ps: Once this is figured out will likely move this to a scope for Product
class Product < ActiveRecord::Base
has_many :connections, dependent: :destroy, as: :connectionable
has_many :genders, through: :connections
scope :with_genders, -> (end_a, end_b) {
relation = joins('INNER JOIN connections c1 ON c1.connectionable_id = products.id AND c1.connectionable_type = \'Product\'')
.joins('INNER JOIN connections c2 ON c1.connectionable_id = c2.connectionable_id AND c2.connectionable_type = \'Product\'')
.where(c1: {gender_id: end_a}, c2: {gender_id: end_b})
.group('products.id')
end_a == end_b ? relation.having('COUNT(products.id) > 1') : relation
}
end
I have the following AR models:
class Checkin < ActiveRecord::Base
belongs_to :user
end
class User < ActiveRecord::Base
has_many :checkins
end
Let's say I have a complex query on checkins and users, for example, Checkin.nearby.today and User.friends_of(john). Is there a straightforward way I can derive an ActiveRecord::Relation of Users? The end result would be friends of John who have checked in nearby today.
I would like the end result to be an instance of ActiveRecord::Relation.
Thanks!
This should do it:
users = User.friends_of(john)
users = users.joins(:checkins).where(checkins: { checkin_date: Date.today })
users = users.where( # your logic to determine the nearby )
As you can see, there is the logic about the nearby scope missing.
In a custom method:
def self.friends_checked_nearby_at_date(friend, nearby = true, date = Date.today)
users = User.friends_of(friend)
users = users.joins(:checkins).where(checkins: { checkin_date: date })
users = users.where( # your logic for the nearby scope ) if nearby.present?
return users
end
# usage:
User.friends_checked_nearby_at_date( User.first )
# or
User.friends_checked_nearby_at_date( User.first, true, Date.today-1.week )
# or
User.friends_checked_nearby_at_date( User.first, false )
# etc.
#find the most recent news item for a specific locale
def self.find_most_recent_news_for_locale
first(:include => :news_item_detail,:conditions => ["news_items.created_at= ? AND news_item_details.locale = ?", maximum(:created_at), I18n.locale])
end
The Models
class NewsItem < ActiveRecord::Base
has_one :news_item_detail
end
class NewsItemDetail < ActiveRecord::Base
belongs_to :news_item
end
In Rails 3, you should use the where method for creating conditions:
def self.find_most_recent_news_for_locale
where("news_items.created_at = ? AND news_item_details.locale = ?",
maximum(:created_at),
I18n.locale).includes(:news_item_details).first
end
You might want to watch episode #202 of Railscasts as a quick tutorial.