I'm having a little trouble with a query in Rails.
Actually my problem is:
I want to select all users which do not have any user_plans AND his role.name is equals to default... OR has user_plans and all user_plans.expire_date are lower than today
user has_many roles
user has_many user_plans
users = User.where(gym_id: current_user.id).order(:id)
#users = []
for u in users
if u.roles.pluck(:name).include?('default')
add = true
for up in u.user_plans
if up.end_date > DateTime.now.to_date
add = false
end
end
if add
#users << u
end
end
end
This code up here, is doing exactly what I need, but with multiple queries.
I don't know how to build this in just one query.
I was wondering if it is possible to do something like
where COUNT(user_plans.expire_date < TODAY) == 0
User.joins(:user_plans, :roles).where("roles.name = 'default' OR user_plans.expire_date < ?", Date.today)
Should work, not tested, but should give you some idea you can play with (calling .distinct at the end may be necessary)
There is also where OR in Rails 5:
User.joins(:user_plans, :roles).where(roles: { name: 'default' }).or(
User.joins(:user_plans).where('user_plans.expire_date < ?', Date.today)
)
FYI: Calling .joins on User will only fetch those users who have at least one user_plan (in other words: will not fetch those who have no plans)
Related
So I'm trying to improve the search feature for my app
My model relationships/associations are like so (many>one, one=one):
Clients < Projects < Activities = Assignments = Users
Assignments < Tasks
Tasks table has only a foreign key to assignments.
Search params look something like this:
params[:search]==User: 'user_handle', Client: 'client_name', Project: 'project_name', Activity: 'activity_name'
So I need to porbably search Clients.where().tasks, Projects.where().tasks and so on.
Then I need to somehow concatenate those queries and get rid of all the duplicate results. How to do that in practice however, I have no clue.
I've been hitting my head against a brick wall with this and internet searches didn't really help... so any help is greatly apreciated. Its probably a simple solution too...
I am on rails 4.2.5 sqlite for dev pg for production
A few things I would change/recommend based on the code in your own answer:
Move the search queries into scopes on each model class
Prefer AREL over raw SQL when composing queries (here's a quick
guide)
Enhance rails to use some sort of or when querying Models
The changes I suggest will enable you to do something like this:
search = search_params
tasks = Tasks.all
tasks = tasks.or.user_handle_matches(handle) if (handle = search[:user].presence)
tasks = tasks.or.client_name_matches(name) if (name = search[:client].presence)
tasks = tasks.or.project_name_matches(name) if (name = search[:project].presence)
tasks = tasks.or.activity_name_matches(name) if (name = search[:activity].presence)
#tasks = tasks.uniq
First, convert each of your queries to a scope on your models. This enables you to reuse your scopes later:
class User
scope :handle_matches, ->(handle) {
where(arel_table[:handle].matches("%#{handle}%"))
}
end
class Client
scope :name_matches, ->(name) {
where(arel_table[:name].matches("%#{name}%"))
}
end
class Project
scope :name_matches, ->(name) {
where(arel_table[:name].matches("%#{name}%"))
}
end
class Activity
scope :name_matches, ->(name) {
where(arel_table[:name].matches("%#{name}%"))
}
end
You can then use these scopes on your Task model to allow for better searching capabilities. For each of the scopes on Task we are doing an join (inner join) on a relationship and using the scope to limit the results of the join:
class Task
belongs_to :assignment
has_one :user, :through => :assignment
has_one :activity, :through => :assignment
has_one :project, :through => :activity
scope :user_handle_matches, ->(handle) {
joins(:user).merge( User.handle_matches(handle) )
}
scope :client_name_matches, ->(name) {
joins(:client).merge( Client.name_matches(name) )
}
scope :activity_name_matches, ->(name) {
joins(:activity).merge( Activity.name_matches(name) )
}
scope :project_name_matches, ->(name) {
joins(:project).merge( Project.name_matches(name) )
}
end
The final problem to solve is oring the results. Rails 4 and below don't really allow this out of the box but there are gems and code out there to allow this functionality.
I often include the code in this GitHub gist in an initializer to allow oring of scopes. The code allows you to do things like Person.where(name: 'John').or.where(name: 'Jane').
Many other options are discussed in this SO question.
If you don't want include random code and gems, another option is to pass an array of ids into the where clause. This generates a query similar to SELECT * FROM tasks WHERE id IN (1, 4, 5, ...):
tasks = []
tasks << Tasks.user_handle_matches(handle) if (handle = search[:user].presence)
tasks << tasks.or.client_name_matches(name) if (name = search[:client].presence)
tasks << tasks.or.project_name_matches(name) if (name = search[:project].presence)
tasks << tasks.or.activity_name_matches(name) if (name = search[:activity].presence)
# get the matching id's for each query defined above
# this is the catch, each call to `pluck` is another hit of the db
task_ids = tasks.collect {|query| query.pluck(:id) }
tasks_ids.uniq!
#tasks = Tasks.where(id: tasks_ids)
So I solved it, it is supper sloppy however.
first I wrote a method
def add_res(ar_obj)
ar_obj.each do |o|
res += o.tasks
end
return res
end
then I wrote my search logic like so
if !search_params[:user].empty?
query = add_res(User.where('handle LIKE ?', "%#{search_params[:user]}%"))
#tasks.nil? ? #tasks=query : #tasks=#tasks&query
end
if !search_params[:client].empty?
query = add_res(Client.where('name LIKE ?', "%#{search_params[:client]}%"))
#tasks.nil? ? #tasks=query : #tasks=#tasks&query
end
if !search_params[:project].empty?
query = add_res(Project.where('name LIKE ?', "%#{search_params[:project]}%"))
#tasks.nil? ? #tasks=query : #tasks=#tasks&query
end
if !search_params[:activity].empty?
query = add_res(Activity.where('name LIKE ?', "%#{search_params[:activity]}%"))
#tasks.nil? ? #tasks=query : #tasks=#tasks&query
end
if #tasks.nil?
#tasks=Task.all
end
#tasks=#tasks.uniq
If someone can provide a better answer I would be forever greatful
I have a ressource Room that has_many reservations. Likewise the ressource Reservation belongs_to a room.
My reservation model has a starts_at and an ends_at attribute.
In my index action for the Room controller I want to get all the Rooms and include all the reservations for a certain date(the date is given as a parameter).
I have tried this code, but it doesn't seem to work as intended.
#rooms = Room.includes(:reservations).where("reservations.starts_at" => params[:date])
I am aware that this code does not take into account that a room could be reserved for multiple days, but I had to start somewhere.
SUM UP
Based on a date the action should return all the rooms, but only include the reservations that is relevant for that date.
EDIT
This is what I ended up doing.
controllers/rooms_controller.rb
def index
#rooms = Room.includes(:reservations)
#date = params[:date] ||= Date.today
end
views/rooms/index.html.haml
- #rooms.each do |room|
- room.reservations.relevant(#date).each do |reservation|
= reservation.id
models/reservation.rb
def self.relevant(date = Date.today)
if date.blank?
date = Date.today
end
where(
'(starts_at BETWEEN ? AND ?) OR (ends_at BETWEEN ? AND ?)',
date.to_date.beginning_of_day, date.to_date.end_of_day,
date.to_date.beginning_of_day, date.to_date.end_of_day
)
end
It works alright, but the view is talking to the model I think?
If your where conditions refer to another table then you also need to need to specify references as well as includes. e.g.
#rooms = Room.includes(:reservations).
where("reservations.starts_at" => params[:date]).
references(:reservations)
See the API documentation here.
I am new to ruby on rails and I'm not sure where to start with this. I have a model for users, and one for projects. Users have many projects, and projects have one user. There is an end_date column in the projects table (as well as a name column).
What I want to do is find the project with the nearest end_date and display it's name and end date on the user's show page.
I tried putting this code in the projects controller, but I do not know if it is working, because I don't know how to access it and display the project name in the view.
def next_deadline(after = DateTime.now, limit = 1)
find(:all, :conditions => ['end_date > ?', after], :limit => limit)
end
Any help would be appreciated. Let me know if more information is needed.
As #Dan mentioned, you do need the :order clause to get the first one, but you should add it to your query and not replace the :conditions (otherwise you'll get the project with the earliest end_date irrespective of your after argument). The way you're defining this method is a bit off though. It should be defined in your Project model (and definitely not the controller) as a class method, or, what I think is a better approach, as a scope. In Rails < 3 (which it seems that you're using):
class Project < ActiveRecord::Base
named_scope :next_deadline, Proc.new { |after = DateTime.now, limit = 1| {:conditions => ['end_date > ?', after], :order => "end_date ASC", :limit => limit} }
...
end
Or in Rails >= 3:
class Project < ActiveRecord::Base
scope :next_deadline, Proc.new { |after = DateTime.now, limit = 1| where('end_date > ?', after).order("end_date ASC").limit(limit) }
...
end
Also, you can always test this kind of code using the Rails console: script/console in Rails < 3, rails c in Rails >= 3.
#projects = Project.find_by_sql("SELECT projects.* FROM projects
JOIN users ON users.id = projects.user_id AND projects.user_id = " + #user.id.to_s + "
WHERE projects.end_date > now()
ORDER BY projects.end_date ASC
LIMIT " + limit)
or
#projects = Project.where(:user_id => #user.id)
.where("end_date > ?", DateTime.now)
.order("end_date ASC")
You want to use :order, not :conditions.
Model.find(:all , :order => "end_date ASC")
Then the first result will be the item with the closest end_date
As Dan said, the condition you wrote won't get the nearest end date, but the dates that are greater than today, or the date passed in as a parameter.
In your User model you could write
def next_deadline_project
self.projects.first
end
as long as you give projects a default scope that orders records by end_date
In order to show information on the view you must set it in an instance variable in the User's controller show method. Instance variables are passed to views and you can access them to display the data.
#project = next_deadline_project
And in your show.html.erb you can use something like:
<%= #project.name %> - <%= #project.end_date %>
I'm having real trouble pulling out a set of records that are self-referentially related to a user in order to show these on a user's 'show' page.
Here's the idea:
Users (current_user) rate the compatibility between two other users (user_a and user_b). They can rate compatibility either positively or negatively: rating two users "compatible" creates a positive_connection between user_a and user_b, and rating them "incompatible" creates a negative_connection. So there are models for positive_connection, negative_connection and user.
Now I need to display only users that are overall_positively_connected_to(#user) (i.e. where positive_connections_to(#user).count > negative_connections_to(#user).count).
This is where I've got to, but I can't get any further:
User model:
def overall_positive_connected_to(user)
positive_connections_to(user).count > negative_connections_to(user).count
end
def positive_connections_to(user)
positive_connections.where("user_b_id = ?", user)
end
def negative_connections_to(user)
negative_connections.where("user_b_id = ?", user)
end
Controller
#user.user_bs.each do |user_b|
if user_b.overall_pos_connected_to(#user)
#compatibles = user_b
end
end
The code in the controller is clearly wrong, but how should I go about doing this? I'm completely new to rails (and sql), so may have done something naive.
Any help would be great.
So am I right in saying you have 3 models
User (id, name)
PositiveConnection (user_a_id, user_b_id)
NegativeConnection (user_a_id, user_b_id)
Or something of that sort.
I think you just want 2 models
and for convenience I'm going to rename the relations as "from_user" and "to_user"
User (id, name)
Connection (value:integer, from_user_id, to_user_id)
Where value is -1 for a negative
and +1 for a positive.
Now we can have do something like
(note: you need to sort out the exact syntax, like :foreign_key, and :source, and stuff)
class User
has_many :connections, :foreign_key => "from_user_id"
has_many :connected_users, :through => :connections, :source => :to_user
def positive_connections
connections.where(:value => 1)
end
def negative_connections
...
end
end
But we also now have a framework to create a complex sql query
(again you need to fill in the blanks... but something like)
class User
def positive_connected_users
connected_users.joins(:connections).group("from_user_id").having("SUM(connections.value) > 0")
end
end
this isn't quite going to work
but is kind of pseudo code for a real solution
(it might be better to think in pure sql terms)
SELECT users.* FROM users
INNER JOIN connections ON to_user_id = users.id
WHERE from_user_id = #{user.id}
HAVING SUM(connections.value) > 0
I'm new to rails and am unsure of the best way of doing this. I have a User which "has many" Events. I want to be able to go user.active? in a view which will display whether the user has one or more associated Events created in the last 5 minutes.
I know the syntax isn't correct but this is what I've got so far:
def active?
find(:conditions => {:events => ["created_at >= ?", DateTime.now - 5.minute]}).count > 0
end
You can just do a find on the events collection:
def active?
events.where('created_at >= ?', 5.minutes.ago).count > 0
end