In my Rails 3.2 app a Connector has_many Incidents.
To get all incidents of a certain connector I can do this:
(In console)
c = Connector.find(1) # c.class is Connector(id: integer, name: string, ...
i = c.incidents.all # all good, lists incidents of c
But how can I get all incidents of many connectors?
c = Connector.find(1,2) # works fine, but c.class is Array
i = c.incidents.all #=> NoMethodError: undefined method `incidents' for #<Array:0x4cc15e0>
Should be easy! But I don't get it!
Here’s the complete code in my statistics_controller.rb
class StatisticsController < ApplicationController
def index
#connectors = Connector.scoped
if params['connector_tokens']
logger.debug "Following tokens are given: #{params['connector_tokens']}"
#connectors = #connectors.find_all_by_name(params[:connector_tokens].split(','))
end
#start_at = params[:start_at] || 4.weeks.ago.beginning_of_week
#end_at = params[:end_at] || Time.now
##time_line_data = Incident.time_line_data( #start_at, #end_at, 10) #=> That works, but doesn’t limit the result to given connectors
#time_line_data = #connectors.incidents.time_line_data( #start_at, #end_at, 10) #=> undefined method `incidents' for #<ActiveRecord::Relation:0x3f643c8>
respond_to do |format|
format.html # index.html.haml
end
end
end
Edit with reference to first 3 answers below:
Great! With code below I get an array with all incidents of given connectors.
c = Connector.find(1,2)
i = c.map(&:incidents.all).flatten
But idealy I'd like to get an Active Records object instead of the array, because I'd like to call where() on it as you can see in methode time_line_data below.
I could reach my goal with the array, but I would need to change the whole strategy...
This is my time_line_data() in Incidents Model models/incidents.rb
def self.time_line_data(start_at = 8.weeks.ago, end_at = Time.now, lim = 10)
total = {}
rickshaw = []
arr = []
inc = where(created_at: start_at.to_time.beginning_of_day..end_at.to_time.end_of_day)
# create a hash, number of incidents per day, with day as key
inc.each do |i|
if total[i.created_at.to_date].to_i > 0
total[i.created_at.to_date] += 1
else
total[i.created_at.to_date] = 1
end
end
# create a hash with all days in given timeframe, number of incidents per day, date as key and 0 as value if no incident is in database for this day
(start_at.to_date..end_at.to_date).each do |date|
js_timestamp = date.to_time.to_i
if total[date].to_i > 0
arr.push([js_timestamp, total[date]])
rickshaw.push({x: js_timestamp, y: total[date]})
else
arr.push([js_timestamp, 0])
rickshaw.push({x: js_timestamp, y: 0})
end
end
{ :start_at => start_at,
:end_at => end_at,
:series => rickshaw #arr
}
end
As you only seem to be interested in the time line data you can further expand the map examples given before e.g.:
#time_line_data = #connectors.map do |connector|
connector.incidents.map do |incident|
incident.time_line_data(#start_at, #end_at, 10)
end
end
This will map/collect all the return values of the time_line_data method call on all the incidents in the collection of connectors.
Ref:- map
c = Connector.find(1,2)
i = c.map(&:incidents.all).flatten
Related
I'm doing checks for empty parameters before do the query.
There is only 1 check for params[:car_model_id]. I can imagine if I will add more checks for other params, then there will be a mess of if-else statements. It doesn't look nice and I think it can be optimized. But how? Here is the code of controller:
class CarsController < ApplicationController
def search
if params[:car_model_id].empty?
#cars = Car.where(
used: ActiveRecord::Type::Boolean.new.cast(params[:used]),
year: params[:year_from]..params[:year_to],
price: params[:price_from]..params[:price_to],
condition: params[:condition]
)
else
#cars = Car.where(
used: ActiveRecord::Type::Boolean.new.cast(params[:used]),
car_model_id: params[:car_model_id],
year: params[:year_from]..params[:year_to],
price: params[:price_from]..params[:price_to],
condition: params[:condition]
)
end
if #cars
render json: #cars
else
render json: #cars.errors, status: :unprocessable_entity
end
end
end
The trick would be to remove the blank values, do a little bit of pre-processing (and possibly validation) of the data, and then pass the params to the where clause.
To help with the processing of the date ranges, you can create a method that checks both dates are provided and are converted to a range:
def convert_to_range(start_date, end_date)
if start_date && end_date
price_from = Date.parse(price_from)
price_to = Date.parse(price_to)
price_from..price_to
end
rescue ArgumentError => e
# If you're code reaches here then the user has invalid date and you
# need to work out how to handle this.
end
Then your controller action could look something like this:
# select only the params that are need
car_params = params.slice(:car_model_id, :used, :year_from, :year_to, :price_from, :price_to, :condition)
# do some processing of the data
year_from = car_params.delete(:year_from).presence
year_to = car_params.delete(:year_to).presence
car_params[:price] = convert_to_range(year_from, year_to)
price_from = car_params.delete(:price_from).presence
price_to = car_params.delete(:price_to).presence
car_params[:price] = convert_to_range(price_from, price_to)
# select only params that are present
car_params = car_params.select {|k, v| v.present? }
# search for the cars
#cars = Car.where(car_params)
Also, I'm pretty sure that the used value will automatically get cast to boolean for you when its provided to the where.
Also, #cars is an ActiveRecord::Relation which does not have an errors method. Perhaps you mean to give different results based on whether there are any cars returned?
E.g: #cars.any? (or #cars.load.any? if you don't want to execute two queries to fetch the cars and check if cars exist)
Edit:
As mentioned by mu is too short you can also clean up your code by chaining where conditions and scopes. Scopes help to move functionality out of the controller and into the model which increases re-usability of functionality.
E.g.
class Car > ActiveRecord::Base
scope :year_between, ->(from, to) { where(year: from..to) }
scope :price_between, ->(from, to) { where(price: from..to) }
scope :used, ->(value = true) { where(used: used) }
end
Then in your controller:
# initial condition is all cars
cars = Cars.all
# refine results with params provided by user
cars = cars.where(car_model_id: params[:car_model_id]) if params[:car_model_id].present?
cars = cars.year_between(params[:year_from], params[:year_to])
cars = cars.price_between(params[:price_from], params[:price_to])
cars = cars.used(params[:used])
cars = cars.where(condition: params[:condition]) if params[:condition].present?
#cars = cars
I have a simple query that Rails seems to be interpreting as a fixnum, but I'm not sure why. My code looks like this:
#user_with_points = Point.select("sum(points) as points, user_id").order("points desc").group("user_id")
#user_with_points.each_with_index do |user_with_point, index|
When I add puts #user_with_points, it shows:
#<Point:0x6360138>
#<Point:0x6322f38>
However, I'm receiving this error this error:
NoMethodError: undefined method 'each' for 75:Fixnum
adding Entire Code
def self.update_overall_rank_and_points
#user_with_points = Point.select("sum(points) as points, user_id").order("points desc").group("user_id")
rank = 0
points = 0
#user_with_points.each_with_index do |user_with_point, index|
#user = User.find(user_with_point.user_id)
if user_with_point.points != points
points = user_with_point.points
rank += 1
end
#user.rank = rank
#user.points = user_with_point.points
#user.save
end
end
Your query is returning a scalar value which the sum of points as an integer. The total of your query happens to be 75, hence the error. Therefore you can't do an each against it since it's not an enumeration.
Try:
#user_with_points = Point.sum(:points, :group => :user_id, :order => 'sum(points)')
#user_with_points.each do |user_id, points|
#...
user = User.find(user_id)
if user.points != points
puts "not equal!"
end
end
I am writing a "Punch Clock" application for my office.. I am working on the controller for the "TIme Card" view which should list a users punches for a given week, and total DAILY then add the TOTAL for the week. I have figured out how to get the time diff between all of the punches with slice/map, my issue is that when I try to do this on the ordered hash (grouped by days) I get undefined method `created_at' for #, I know I must be missing some syntax somewhere, your help is greatly appreciated...
Here is my controller...
Note that if i call #in_out_lenghts on #punches, this works and gives me the total for the week, but #punches_days gives me an error, therefore I can not keep a running tally....
def mytimecard
#week = params[:week].to_s
if #week == "lastweek"
#punches = Punch.lastweek.where("user_id = ?", params[:user])
else
#punches = Punch.thisweek.where("user_id = ?", params[:user])
end
#punches_days = #punches.group_by { |t| t.created_at.beginning_of_day}
if #punches.count%2 == 0
#in_out_lengths = #punches_days.each_slice(2).map { |a|(a[1].created_at).round(15.minutes) - (a[0].created_at).round(15.minutes) }
#total = ((#in_out_lengths.inject(:+))/60/60)
else
#total = "Can Not Calculate, Odd Number of Punches"
end
respond_to do |format|
format.html # timecard.html.erb
format.json { render :json => #punches }
end
end
group_by will return a hash of days and punches.
{ :day_1 => [ :punch1, :punch2], :day_2 => [ :punch3, :punch4, :punch5 ] }
doing an each_slice and a map will result in some sort of array, but probably not what you meant.
You may have meant to count the number of punches and call something like this
Punch.lastweek.where("user_id = ?", params[:user]).group('date(created_at)')
This would have resulted in the date => punches_count format, at least with mysql.
In my controller I'd like to do something like the following:
#book = Book.find(:all, :conditions = > [" created_at > with in the last 1 minute "]
if #book.nil?
# Just incase we didn't create a book, we'll initialize one
#book = Book.create()
end
#chapters = #book.chapters.build etc.............
* In sum, when the user is uploading a chapter, if they've recently created a book, I want the chapter to automatically go to that book and to make a new book.
Thoughts? thank you all
Hi Your code may be something like
time = Time.now
#book = Book.find(:all, :conditions = > [" created_at >= '#{Time.utc(time.year, time.month, time.day, time.hour, time.min - 1)}'"]) // .first if you're sure that it'll return just one record
if #book.blank? //.blank? not .nil? because the result of find is [] not nil
# Just incase we didn't create a book, we'll initialize one
#book = Array.new() //if you're sure that find'll return just one book you may don't change your code here
#book.first = Book.create()
end
//if you're sure that find'll return just one book you may don't change your code here
#book.each do |book|
#chapters = #book.chapters.build etc.............
end
if you're looking for a book created by some user you must pass user_id to this method and your conditions'll be
:conditions = > [" created_at >= '?' AND author_id = ?", Time.utc(time.year, time.month, time.day, time.hour, time.min - 1), params[:author_id]])
I have a model that would look something like:
my_diet = Diet.new
my_diet.food_type_1 = "beef"
my_diet.food_type_1_percentage = 40
my_diet.food_type_2 = "carrots"
my_diet.food_type_2_percentage = 50
my_diet.food_type_3 = "beans"
my_diet.food_type_3_percentage = 5
my_diet.food_type_4 = "chicken"
my_diet.food_type_4_percentage = 5
I need to find which food_type has the highest percentage. So far I've tried creating a hash out of the attibutes and percentages then sorting the hash (see below) but it feels like there must be a cleaner way to do it.
food_type_percentages = { :food_type_1 => my_diet.foo_type_percentage_1_percentage.nil? ? 0 : my_dient.food_type_1_percentage,
:food_type_2 => my_diet.foo_type_percentage_2_percentage.nil? ? 0 : my_dient.food_type_2_percentage,
:food_type_3 => my_diet.foo_type_percentage_3_percentage.nil? ? 0 : my_dient.food_type_3_percentage,
:food_type_4 => my_diet.foo_type_percentage_4_percentage.nil? ? 0 : my_dient.food_type_4_percentage
}
food_type_percentages.sort {|a,b| a[1]<=>b[1]}.last
Any ideas?
Thanks!
To find the max value amongst columns of an existent row in the DB, do the following:
d = Diet.first(:select => "*, GREATEST(
food_type_1_percentage,
food_type_2_percentage,
food_type_3_percentage,
food_type_4_percentage) AS top_food_type_percentage,
CASE GREATEST(
food_type_1_percentage,
food_type_2_percentage,
food_type_3_percentage,
food_type_4_percentage)
WHEN food_type_1_percentage THEN food_type_1
WHEN food_type_2_percentage THEN food_type_2
WHEN food_type_3_percentage THEN food_type_3
WHEN food_type_4_percentage THEN food_type_4
END AS top_food_type")
d.top_food_type # carrots
d.top_food_type_percentage # 50
If you are trying to find the top food type in the current model instance then
class Diet < ActiveRecord::Base
def top_food_type
send(top_food_type_col)
end
def top_food_type_percentage
send("#{top_food_type_col}_percentage")
end
FOOD_TYPE_COL = %w(food_type_1 food_type_2 food_type_3 food_type_4)
def top_food_type_col
#top_food_type_col ||= FOOD_TYPE_COL.sort do |a, b|
send("#{a}_percentage") <=> send("#{b}_percentage")
end.last
end
end
Now you can do the following:
d = Diet.new
....
....
....
d.top_food_type # carrots
d.top_food_type_percentage # 50
I assume food_percentage is the column
if you just want to find out ref this
Diet.maximum('food_percentage') # gives 50
OR you want complete record use this
Diet.find(:first, :order=> 'food_percentage DESC', :limit=>1)