Map a rails collection by date - ruby-on-rails

I have an employee model and a sales model, an employee has_many sales. I want to pull the weekly sales for each employee,
so far I can get a collection of all the sales for the current week for each employee;
def weekly_sales
self.sales.where(created_at: (Date.today.beginning_of_week..(Date.today.beginning_of_week + 5)))
end
which gives;
<ActiveRecord::AssociationRelation [#<Sale id: 1054, amount: 2668, new_sale: true, created_at: "2015-07-21 00:00:00", updated_at: "2015-07-21 11:48:03", employee_id: 17>, #<Sale id: 1053, amount: 7128, new_sale: false, created_at: "2015-07-21 00:00:00", updated_at: "2015-07-21 11:48:03", employee_id: 17>, #<Sale id: 1052, amount: 4781, new_sale: true, created_at: "2015-07-20 00:00:00", updated_at: "2015-07-21 11:48:03", employee_id: 17>, #<Sale id: 1051, amount: 4491, new_sale: true, created_at: "2015-07-20 00:00:00", updated_at: "2015-07-21 11:48:03", employee_id: 17>]>
I want to end up with an array that has 5 elements, each is the sale.amount total for each day monday to friday but I'm not sure how to correctly build it.
Runninng weekly sales on a tuesday would give a 5 element array e.g [ 350,290,0,0,0]


This will give you a hash, with dates as keys, and values, which are the sum of sales for this date (and it only makes one query to the db):
def weekly_sales
sales.group("DATE(created_at)").count
end
To get the sum of all sales, grouped by date:
def weekly_sales
sales.group("DATE(created_at)").sum(:amount)
end


i hope this one will give you your desired output
def weekly_sales
self.sales.where(created_at: (Date.today.beginning_of_week..(Date.today.beginning_of_week + 5))).group("DATE(sales.created_at)").sum("sales.amount")
end

Related

Bring the user name when query an item in Rails

I have an endpoint the returns all the comments on a blog. I would like to have the name of the user that made the comment. Is there a way to bring it all together when hitting that comments endpoint or do I have to make another query for each comment?
def comments
#comments = #blog.comments
render json: { comments: #comments }
end
This is what doing #blog.comments returns
[#<Comment id: 1, content: "This is a very good post", created_at: "2020-09-11 01:55:56", updated_at: "2020-09-11 01:55:56", blog_id: 3, user_id: 1>, #<Comment id: 2, content: "I agree with all of this", created_at: "2020-09-11 01:55:56", updated_at: "2020-09-11 01:55:56", blog_id: 3, user_id: 1>, #<Comment id: 3, content: "I don't agree with all of this", created_at: "2020-09-11 01:55:56", updated_at: "2020-09-11 01:55:56", blog_id: 3, user_id: 1>]>

Assuming you have a users table with a field users.name, and a belongs_to :user relationship on your model comment:
Just replace the line
#comments = #blog.comments
with
#comments = #blog.comments.select('comments.*, users.name').joins(:user)

Making leader board

I'm working with Stats of players and I got this data.
Stat model = id: integer, pts: float, user_id: integer, created_at: datetime, updated_at: datetime
So there is a chance that user_id has 2 or more data.
{id: 1, pts: 2, user_id: 1, created_at: datetime, updated_at: datetime}
{id: 2, pts: 8, user_id: 1, created_at: datetime, updated_at: datetime}
{id: 3, pts: 10, user_id: 2, created_at: datetime, updated_at: datetime}
I need to get the average pts per user_id then order it by pts. To get the top scorer.
EDIT
I've fixed this using:
stat = Stat.group(:user_id).sum("pts")
new_value = Hash[*stat.sort_by { |k,v| -v }[0..9].flatten] # To get top 1 to 10
Thank you!

You can do it with a simple query:
hash = Stat.group("user_id").average('pts')
Its will return a hash containing user_id as key and their average points scored as value.
Now to order you can order this hash as:
Hash[h.sort_by{|k, v| v.to_i}.reverse]
This will return a hash sorted in descending order by points.That means the first element in the hash would be the top scorer.
Note: v.to_i is use to handle nil cases.

Try this...
Stat.group(:user_id).order('average_pts DESC').average(:pts)

Other option.
In controller:
#users = User.joins(:stats).select("users.*, stats.user_id, stats.pts, AVG(stats.pts) avg_pts").group('stats.user_id').order("avg_pts DESC")
In view, to be formatted as you like:
<% #users.each do |user| %>
<p><%= user.name %> | <%= user.avg_pts %></p>
<% end %>

Datetime from params not saved correctly in the database

I have the following situation . An user enters a date and time from rails's date and time select boxes and in the controller, method create, i have the following params:
"event"=>
{"title"=>"tet",
"start_date(1i)"=>"2013",
"start_date(2i)"=>"4",
"start_date(3i)"=>"26",
"end_date(1i)"=>"2013",
"end_date(2i)"=>"4",
"end_date(3i)"=>"31",
"start_time(1i)"=>"2013",
"start_time(2i)"=>"4",
"start_time(3i)"=>"26",
"start_time(4i)"=>"10",
"start_time(5i)"=>"05",
"end_time(1i)"=>"2013",
"end_time(2i)"=>"4",
"end_time(3i)"=>"26",
"end_time(4i)"=>"10",
"end_time(5i)"=>"05"}
If i do
#event = Event.new(params[:event])
the output is
=> #<Event id: nil, start_date: "2013-04-26", title: "tet", created_at: nil, updated_at: nil, owner_id: 0, owner_type: "", archived: false, end_date: "2013-05-01", start_time: "2013-04-26 10:05:00", end_time: "2013-04-26 10:05:00">
The end_date is not the same with the one in params
Time.zone
returns
=> (GMT+02:00) Jerusalem
Why does this happen?

There is no April 31, so it probably wraps to the next day after April 30 (May 1)

:autosave ignored on has_many relation -- what am I missing?

I have a pair of classes:
class Collection < ActiveRecord::Base
has_many :items, autosave: true
end
class Item < ActiveRecord::Base
belongs_to :collection
end
From the docs:
When :autosave is true all children is saved, no matter whether they are new records:
But when I update an Item and save its parent Collection, the Item's upated attributes don't get saved:
> c = Collection.first
=> #<Collection id: 1, name: "collection", created_at: "2012-07-23 00:00:10", updated_at: "2012-07-23 00:00:10">
> i = c.items.first
=> #<Item id: 1, collection_id: 1, name: "item1", created_at: "2012-07-23 00:00:25", updated_at: "2012-07-23 00:00:25">
> i.name = 'new name'
=> "new name"
> c.save
=> true
> Collection.first.items
=> [#<Item id: 1, collection_id: 1, name: "item1", created_at: "2012-07-23 00:00:25", updated_at: "2012-07-23 00:00:25">]
So, what am I missing?
I'm using Rails 3.2.5 and Ruby 1.9.2.
So I've done some digging about in the source of ActiveRecord. We can get hold of c's autosave assocations:
> c.class.reflect_on_all_autosave_associations
=> [#<ActiveRecord::Reflection::AssociationReflection:0x007fece57b3bd8 #macro=:has_many, #name=:items, #options={:autosave=>true, :extend=>[]}, #active_record=Collection(id: integer, name: string, created_at: datetime, updated_at: datetime), #plural_name="items", #collection=true, #class_name="Item", #klass=Item(id: integer, collection_id: integer, name: string, created_at: datetime, updated_at: datetime), #foreign_key="collection_id", #active_record_primary_key="id", #type=nil>]
I think this illustrates that the association has been set up for autosaving.
We can then get the instance of the association corresponding to c:
> a = c.send :association_instance_get, :items
=> #<ActiveRecord::Associations::HasManyAssociation:0x007fece738e920 #target=[#<Item id: 1, collection_id: 1, name: "item1", created_at: "2012-07-23 00:00:25", updated_at: "2012-07-23 00:00:25">], #reflection=#<ActiveRecord::Reflection::AssociationReflection:0x007fece57b3bd8 #macro=:has_many, #name=:items, #options={:autosave=>true, :extend=>[]}, #active_record=Collection(id: integer, name: string, created_at: datetime, updated_at: datetime), #plural_name="items", #collection=true, #class_name="Item", #klass=Item(id: integer, collection_id: integer, name: string, created_at: datetime, updated_at: datetime), #foreign_key="collection_id", #active_record_primary_key="id", #type=nil>, #owner=#<Collection id: 1, name: "collection", created_at: "2012-07-23 00:00:10", updated_at: "2012-07-23 00:00:10">, #updated=false, #loaded=true, #association_scope=[#<Item id: 1, collection_id: 1, name: "item1", created_at: "2012-07-23 00:00:25", updated_at: "2012-07-23 00:00:25">], #proxy=[#<Item id: 1, collection_id: 1, name: "item1", created_at: "2012-07-23 00:00:25", updated_at: "2012-07-23 00:00:25">], #stale_state=nil>
We can then find the actual objects that are associated via this association:
> a.target
=> [#<Item id: 1, collection_id: 1, name: "item1", created_at: "2012-07-23 00:00:25", updated_at: "2012-07-23 00:00:25">]
The object found here does not have update that I'd made earlier.

The problem here is the line
i = c.items.first
This line pulls the correct item from the database, but doesn't attach it to the collection c. It is a distinct ruby object from the object
i = c.items[0]
If you replace the first line with the second your example will work.

Update attribute in callback Rails 3

Following on from this question, I have spent the day trying to add a cumulative running sales total to my sales table. It's a bit tricky (for me) because I want a running total for sales where the isbn_id is the same, and, within that set, records where the channel_id is the same - ranked by invoice_date. This is all so I can calculate royalties on a particular range of units sold.
Here's my non-working callback code, in the Sale model:
before_save :runningtotal
private
def runningtotal
#sale = Sale.order("invoice_date ASC")
#lastbal = #sale.find_all_by_isbn_id(#isbn).group_by(&:channel)
#that sucessfully gets all sales ranked by date ascending, then groups them by channel, just for the current isbn.
#lastbal.each do |channel, sale|
sale.each_with_index do |sale, i|
previous_sale = sale[i-1] unless i==0
next unless previous_sale
#total_quantity = previous_sale.quantity + :quantity
write_attribute(:total_quantity,#total_quantity)
end
end
end
Is this roughly how a callback should be written - just in the model? Does it just run magically before_save of a new sale?
My core question is: how can I update the attribute "total_quantity" to be the sum of "quantity" for the current record, and "total_quantity" for the previous record by date, in a before_save callback, within the constraints of the finds for isbn_id and channel_id?
Here's the output of the find:
ruby-1.9.2-p180 :025 > #lastbal = #sale.find_all_by_isbn_id(#isbn).group_by(&:channel)
=> {#<Channel id: 4, isbn_id: nil, channel_name: "Gratis", created_at: "2011-05-26 11:08:22", updated_at: "2011-05-26 11:08:22">=>[#<Sale id: 26, isbn_id: 2, quantity: 10000, value: 40000, currency: "", total_quantity: nil, created_at: "2011-05-26 11:11:30", updated_at: "2011-05-26 11:11:30", customer: "6", retail_price: nil, discount: nil, channel_id: 4, invoice_date: "2011-05-18", rule_id: nil, trenche: nil>], #<Channel id: 1, isbn_id: nil, channel_name: "Home", created_at: "2011-05-16 19:47:27", updated_at: "2011-05-16 19:47:27">=>[#<Sale id: 22, isbn_id: 2, quantity: 1000, value: 5193, currency: "", total_quantity: nil, created_at: "2011-05-25 19:46:03", updated_at: "2011-05-25 19:46:03", customer: "a", retail_price: nil, discount: nil, channel_id: 1, invoice_date: "2011-05-11", rule_id: nil, trenche: nil>, #<Sale id: 24, isbn_id: 2, quantity: 1000, value: 4394, currency: "", total_quantity: nil, created_at: "2011-05-26 09:48:16", updated_at: "2011-05-26 09:48:16", customer: "g", retail_price: nil, discount: nil, channel_id: 1, invoice_date: "2011-05-10", rule_id: nil, trenche: nil>, #<Sale id: 25, isbn_id: 2, quantity: 1000, value: 4394, currency: "", total_quantity: nil, created_at: "2011-05-26 10:02:38", updated_at: "2011-05-26 10:02:38", customer: "g", retail_price: nil, discount: nil, channel_id: 1, invoice_date: "2011-05-05", rule_id: nil, trenche: nil>, #<Sale id: 21, isbn_id: 2, quantity: 1000, value: 5193, currency: "", total_quantity: nil, created_at: "2011-05-25 14:12:45", updated_at: "2011-05-25 14:12:45", customer: "a", retail_price: nil, discount: nil, channel_id: 1, invoice_date: "2010-10-15", rule_id: nil, trenche: nil>, #<Sale id: 13, isbn_id: 2, quantity: 50, value: 159, currency: "", total_quantity: nil, created_at: "2011-05-25 12:33:09", updated_at: "2011-05-25 12:33:09", customer: "a", retail_price: nil, discount: nil, channel_id: 1, invoice_date: "2010-01-01", rule_id: nil, trenche: nil>, #<Sale id: 14, isbn_id: 2, quantity: 25, value: 129, currency: "", total_quantity: nil, created_at: "2011-05-25 12:33:23", updated_at: "2011-05-25 12:33:23", customer: "", retail_price: nil, discount: nil, channel_id: 1, invoice_date: "2010-01-01", rule_id: nil, trenche: nil>, #<Sale id: 12, isbn_id: 2, quantity: 100, value: 415, currency: "", total_quantity: nil, created_at: "2011-05-25 12:32:50", updated_at: "2011-05-25 15:13:21", customer: "a", retail_price: nil, discount: nil, channel_id: 1, invoice_date: "2001-10-01", rule_id: nil, trenche: nil>, #<Sale id: 11, isbn_id: 2, quantity: 500, value: 2197, currency: "", total_quantity: nil, created_at: "2011-05-25 12:32:24", updated_at: "2011-05-25 15:11:20", customer: "a", retail_price: nil, discount: nil, channel_id: 1, invoice_date: "2000-10-01", rule_id: nil, trenche: nil>], #<Channel id: 2, isbn_id: nil, channel_name: "Export", created_at: "2011-05-16 19:47:35", updated_at: "2011-05-16 19:47:35">=>[#<Sale id: 23, isbn_id: 2, quantity: 2000, value: 5000, currency: "", total_quantity: nil, created_at: "2011-05-26 09:16:15", updated_at: "2011-05-26 09:16:15", customer: "v", retail_price: nil, discount: nil, channel_id: 2, invoice_date: "2011-05-02", rule_id: nil, trenche: nil>, #<Sale id: 17, isbn_id: 2, quantity: 242, value: 657, currency: "", total_quantity: nil, created_at: "2011-05-25 12:34:24", updated_at: "2011-05-25 12:34:24", customer: "b ", retail_price: nil, discount: nil, channel_id: 2, invoice_date: "2010-10-15", rule_id: nil, trenche: nil>, #<Sale id: 18, isbn_id: 2, quantity: 54, value: 194, currency: "", total_quantity: nil, created_at: "2011-05-25 12:34:44", updated_at: "2011-05-25 12:34:44", customer: "b ", retail_price: nil, discount: nil, channel_id: 2, invoice_date: "2010-10-15", rule_id: nil, trenche: nil>, #<Sale id: 15, isbn_id: 2, quantity: 135, value: 377, currency: "", total_quantity: nil, created_at: "2011-05-25 12:33:48", updated_at: "2011-05-25 12:33:48", customer: "b ", retail_price: nil, discount: nil, channel_id: 2, invoice_date: "2010-09-15", rule_id: nil, trenche: nil>, #<Sale id: 16, isbn_id: 2, quantity: 433, value: 830, currency: "", total_quantity: nil, created_at: "2011-05-25 12:34:06", updated_at: "2011-05-25 12:34:06", customer: "b ", retail_price: nil, discount: nil, channel_id: 2, invoice_date: "2010-09-15", rule_id: nil, trenche: nil>]}
Here's the columns in my Sale model:
# id :integer not null, primary key
# isbn_id :integer
# quantity :integer
# value :integer
# currency :string(255)
# total_quantity :integer
# created_at :datetime
# updated_at :datetime
# customer :string(255)
# retail_price :integer
# discount :decimal(, )
# channel_id :integer
# invoice_date :date
# rule_id :integer
Thanks so much in advance.
UPDATE: final solution.
Really not sure that this counts as 'giving back to the community' as it's comically verbose, not DRY, full of puts which I used to figure out all the bugs, and badly formatted to boot, but heck, I'm a noob at and the very least I can come back here and laugh at myself in a few years when I know what I'm doing. So, here's my final solution, in Sale.rb. Poor overstuffed model. I will refactor this, one day.
before_save :runningtotal
after_commit :refresh
private
def runningtotal
# get the latest sale that matches the new sale's isbn and channel id, then rank by invoice date descending, and get the first record:
lastsale = Sale.where(:isbn_id => self.isbn_id).where(:channel_id => self.channel_id).order("invoice_date DESC").first
allsales = Sale.where(:isbn_id => self.isbn_id).where(:channel_id => self.channel_id).order("invoice_date DESC")
# set the total_quantity field in the new sales record to its quantity + the last sale's total.
if allsales.maximum(:invoice_date).nil?
puts "runningtotal thinks the max of invoice date in the allsales relation is nil"
puts "and runningtotal is setting total_quantity on the new sale to be #{self.quantity + (lastsale.try(:total_quantity) || 0)}"
self.total_quantity = self.quantity + (lastsale.try(:total_quantity) || 0)
else
if self.invoice_date < allsales.maximum(:invoice_date)
puts "the runningtotal method has been skipped because runningtotal thinks the current invoice date is less than the highest invoice date in the allsales relation"
else
puts "this is a normal entry so runningtotal has set the total quantity to be #{self.quantity + (lastsale.try(:total_quantity) || 0) }"
self.total_quantity = self.quantity + (lastsale.try(:total_quantity) || 0)
end
end
end
def refresh
allsales = Sale.where(:isbn_id => self.isbn_id).where(:channel_id => self.channel_id).order("invoice_date ASC")
#if the runningtotal callback hasn't run, the total quantity will be nil, and nil triggers this after_commit callback
if total_quantity.nil?
puts "running refresh callback"
puts "here's a sample parameter pass: id: #{id} quantity: #{quantity} date: #{invoice_date} "
puts "allsales class is #{allsales.class}"
# if the new sale that's being saved has a date that's before any previous sale...
puts "before the if, refresh thinks that the earliest invoice date is #{allsales.minimum(:invoice_date)} and that invoice date is #{invoice_date}"
if invoice_date <= allsales.minimum(:invoice_date)
puts "date earlier than existing sales dates"
puts "refresh thinks that the earliest invoice date is #{allsales.minimum(:invoice_date)} and that invoice date is #{invoice_date}"
#... then set its total_quantity to the sale quantity...
update_attribute(:total_quantity, quantity)
puts "total_qty updated with qty"
# ... and update all subsequent records' total_quantity (skipping the before_save callback which would trigger an infinite loop).
allsales.each_with_index do |sale, i|
previous_sale = allsales[i-1] unless i==0
next unless previous_sale
puts "getting qty out of arel when date earlier than others: #{previous_sale.quantity}"
puts "this is adding #{quantity} to #{previous_sale.quantity } which is #{quantity + previous_sale.total_quantity }"
Sale.skip_callback(:save, :before, :runningtotal )
sale.update_attribute(:total_quantity, (sale.quantity + previous_sale.total_quantity ))
Sale.set_callback(:save, :before, :runningtotal)
end
else
# if the invoice date is within the min and max range of the previous sales...
# ... update all previous and subsequent records' total_quantity (skipping the before_save callback which would trigger an infinite loop).
allsales.each_with_index do |sale, i|
previous_sale = allsales[i-1] unless i==0
next unless previous_sale
puts "getting qty out of arel within existing date range: #{previous_sale.quantity}"
puts "this is adding #{quantity} to #{previous_sale.quantity } which is #{quantity + previous_sale.total_quantity }"
Sale.skip_callback(:save, :before, :runningtotal )
sale.update_attribute(:total_quantity, (sale.quantity + previous_sale.total_quantity ))
Sale.set_callback(:save, :before, :runningtotal )
end
end
end
end

Yes, using before_save in the model will run that every time it is saved, whether new or updated. Thus you need to watch out in calculations the expect the current (new) record to not exist yet. ;) You might want to use before_save, :on => :create to limit it to the creation action.
However, if I understand your english statement of the problem, your code is rather convoluted. I don't even see where #isbn is set, that could be dangerous...
Does this need to update the total on other objects this isbn and channel? Usually it's better form to simply calculate that as needed rather than trying to cache the total in every record.
within the callback, self is the current (new?) record, so use it to refer to new values.
#sale = Sale.order("invoice_date ASC")
#lastbal = #sale.find_all_by_isbn_id(#isbn).group_by(&:channel)
can be replaced by this, I think:
#lastbal = Sale.order("invoice_date ASC").where(:isbn_id => self.isbn_id).group_by(&:channel)
I'm assuming that #isbn is actually the new record's isbn.
From there, I'm not sure if you are only intending to update the new record or the old ones... If you want to update the current record, just set the attribute and exit the callback, and it will be saved when the rest is saved:
self.total_quantity = previous_sale.quantity + self.quantity
If you are intending to update the other objects too, then we have to update those objects and save them. I don't see that happening at all here in your code.
Your code goes through several loops, possibly hitting the write_attribute several times... that doesn't make sense.
If you mean you want to find the last record that matches the current isbn and channel to update the new record, here's what I would do:
def runningtotal
lastsale = Sale.where(:isbn_id => self.isbn_id).
where(:channel_id => self.channel_id).
order("invoice_date DESC").first
# that should be the latest sale that matches
# the current isbn and channel
self.total_quantity = self.quantity + (lastsale.try(:total_quantity) || 0)
# watch out for nil if no previous record exists ^
end
`

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