In Rails, I get a hash using includes:
<% #teste = UserProfile.includes(:mobile_models).group(:name).count %>
The problem is that includes generates a hash like the following:
{nil=>4774, "2610"=>7, "2626"=>4, "2630"=>5, "2760"=>4, "3250"=>3, "355"=>5, "3I607 BlackJack"=>5, "5230"=>13, "5235"=>4, "5310"=>5, "5500"=>5, "5800 Xpress Music"=>16, "6020"=>4, "6120c"=>4, "6131"=>4, "7210"=>5, "A1200r"=>5, "A1900"=>5, "AIKO 70"=>5, "B3410W Ch#t"=>4, "beTouch E100"=>4, "BlackBerry 8320 (Curve)"=>10,....
In my database, I don't find any mobile record with the name "nil". Checking my database, I can't find what might be producing this nil.
The other goal is to sum all values, like this:
<%= sum = #teste.values.sum %>
But when I do this, the 'nil' is added too.
---Update
models/UserProfile
class UserProfile < ActiveRecord::Base
has_and_belongs_to_many :mobile_models, join_table: 'user_profiles_mobile_models', order: 'name'
models/MobileModel
class MobileModel < ActiveRecord::Base
belongs_to :mobile_maker
Because you are grouping by :name, some of the MobileModel or UserProfile objects have the name attribute set to nil. You will need to check both as without seeing the model definition, I can't tell which model has the :name property you are grouping on. If you can share the model code, I can be more explicit.
If both models have a name attribute, you can be more explicit in your group statement:
UserProfile.includes(:mobile_models).group('mobile_models.name')
or...
UserProfile.includes(:mobile_models).group('user_profiles.name')
Also, if a number of your users do not have any mobile_models to include, I believe they will get dumped into the nil grouping as well.
You are getting that hash because of group(:name).
That means you have 4774 records who's name is nil.
Related
Looks like my form does what is expected to do - sends the right value, but its not being saved in db. Check_box_tag takes data from enum (I use enum because I use same data for select field):
class UserProfile < ApplicationRecord
enum locations: { Kursenai: 0, Papiskes: 1, Versiai: 2 }
And in form_for:
<% UserProfile.locations.each do |key, val| %>
<%= f.label key %>
<%= check_box_tag('user_profile[locations][]', val, false, id: val) %>
<% end %>
But it fails to update:
'["0", "1"]' is not a valid locations
Postgres:
t.integer "locations", array: true
So I thought it fails because row type is integer, but this:
<%= check_box_tag('user_profile[locations][].to_i', val.to_i, false, id: val) %>
removed error but user field :locations is still nil. What do I miss?
Strong params:
..permit(locations: [])
p.s. if you think this could be done in a better way - please feel free to show.
Why?
Because '["0", "1"]' is considered as string and it is not among values you mentioned in enum i.e 0,1,2.
You can't achieve it directly as enum requires field type to hold single value.But in your case it's an array.
How to achieve?
class UserProfile < ApplicationRecord
# value should store as array not as string.
serialize :locations, Array
# define your own enum by creating static var.U can use Array or Hash structure.
# Here I am using Hash.
# ENUM_LOCATIONS = ["Kursenai", "Papiskes", "Versiai"]
ENUM_LOCATIONS = {"Kursenai": 0, "Papiskes": 1, "Versiai": 2}
# Now modify you getter little bit to return enumed values
def locations
res = []
self[:locations].each{|v| ENUM_LOCATIONS.is_a?(Array) ? res << ENUM_LOCATIONS[v.to_i] : res << ENUM_LOCATIONS.key(v.to_i).to_s}
res
end
end
That's it.
Why are you using enum? I think it's better to create a new model Location and connect with UserProfile via HABTM relation. It would fullfill the Database normalization and easier to work with.
Edit:
class UserProfile < ApplicationRecord
has_and_belongs_to_many :locations
end
class Location < ApplicationRecord
has_and_belongs_to_many :user_profiles
end
and you need to create 3 location records
Location.create(name: 'Kursenai')
Location.create(name: 'Papiskes')
Location.create(name: 'Versiai')
Use any standart queries, joins. You can built a form like here:
Rails 4 - checkboxes for has_and_belongs_to_many association
or Multiple select issue with a HABTM relationship using Rails 4
So I'm having a little difficulty using Rails to query some data.
I have two models and I'm attempting to join one on to the other. My issue arises using a group by method. Both models have the same attribute name and this is causing an ambiguous column name error. My query is:
Photo.joins(:votes).group(:photo_id, :image, :title, :bytes, :user_id, :public_id).order("count_all desc").limit(10).count
How can I choose which model that the group by attributes use?
You can specify the table name like this:
Photo.joins(:votes)
.group(:photo_id, :image, :title, :bytes, 'photos.user_id', :public_id)
.order("count_all desc")
.limit(10)
.count
Assuming user_id is the ambiguous column name and photos is the actual tablename.
In my rails app, i am using a legacy database.
class Expression < ActiveRecord::Base
set_table_name "EXPRESSION"
set_primary_key "EXP_ID"
belongs_to :sub, :foreign_key => "EXP_SUB_FK"
end
To save an entry in the 'EXPRESSION' table, i am using the following code in my controller method:
#expression = Expression.create(
:EXP_ID => 7,
:EXP_SUB_FK => 99991886,
:EXP_STRENGTH => 'strong',
:EXP_ADDITIONAL_STRENGTH => 'intense',
:EXP_COMPONENT_ID => 43444
)
I have to manually set the EXP_ID each time i save an entry (i will get the id from another table), but the above code does not save the EXP_ID. All the other values are saved except for the EXP_ID.
If i comment out 'set_primary_key "EXP_ID"' in the Expression model, it works but i need to define EXP_ID as primary key.
Is there a way of allocating a value for a primary key when saving an entry to the dbase?
I would be grateful if anyone can provide me with some hint.
Set the EXP_ID in a before_save filter defined in the the Expression model.
UPDATE:
Added Sample:
before_save :set_exp_id
def set_exp_id
self.exp_id = 5555555
end
I'd like to update a massive set of document on an hourly basis.
Here's the
fairly simple Model:
class Article
include Mongoid::Document
field :article_nr, :type => Integer
field :vendor_nr, :type => Integer
field :description, :type => String
field :ean
field :stock
field :ordered
field :eta
so every hour i get a fresh stock list, where :stock,:ordered and :eta "might" have changed
and i need to update them all.
Edit:
the stocklist contains just
:article_nr, :stock, :ordered, :eta
wich i parse to a hash
In SQL i would have taken the route to foreign keying the article_nr to a "stock" table, dropping the whole stock table, and running a "collection.insert" or something alike
But that approach seems not to work with mongoid.
Any hints? i can't get my head around collection.update
and changing the foreign key on belongs_to and has_one seems not to work
(tried it, but then Article.first.stock was nil)
But there has to be a faster way than iterating over the stocklist array of hashes and doing
something like
Article.where( :article_nr => stocklist['article_nr']).update( stock: stocklist['stock'], eta: stocklist['eta'],orderd: stocklist['ordered'])
UPDATING
You can atomically update multiple documents in the database via a criteria using Criteria#update_all. This will perform an atomic $set on all the attributes passed to the method.
# Update all people with last name Oldman with new first name.
Person.where(last_name: "Oldman").update_all(
first_name: "Pappa Gary"
)
Now I can understood a bit more. You can try to do something like that, assuming that your article nr is uniq.
class Article
include Mongoid::Document
field :article_nr
field :name
key :article_nr
has_many :stocks
end
class Stock
include Mongoid::Document
field :article_id
field :eta
field :ordered
belongs_to :article
end
Then you when you create stock:
Stock.create(:article_id => "123", :eta => "200")
Then it will automaticly get assign to article with article_nr => "123"
So you can always call last stock.
my_article.stocks.last
If you want to more precise you add field :article_nr in Stock, and then :after_save make new_stock.article_id = new_stock.article_nr
This way you don't have to do any updates, just create new stocks and they always will be put to correct Article on insert and you be able to get latest one.
If you can extract just the stock information into a separate collection (perhaps with a has_one relationship in your Article), then you can use mongoimport with the --upsertFields option, using article_nr as your upsertField. See http://www.mongodb.org/display/DOCS/Import+Export+Tools.
I have several similar models ContactEmail, ContactLetter, etcetera.
Each one belongs_to a Contact
Each contact belongs_to a Company
So, what I did was create a virtual attribute for ContactEmail:
def company_name
contact = Contact.find_by_id(self.contact_id)
return contact.company_name
end
Question: How can I get an easy list of all company_name (without duplicates) if I have a set of ContactEmails objects (from a find(:all) method, for example)?
When I try to do a search on ContactEmail.company_name using the statistics gem, for example, I get an error saying that company_name is not a column for ContactEmail.
Assuming your ContactEmail set is in #contact_emails (untested):
#contact_emails.collect { |contact_email| contact_email.company_name }.uniq
You don't need the virtual attribute for this purpose though. ActiveRecord sets up the relationship automatically based on the foreign key, so you could take the company_name method out of the ContactEmail model and do:
#contact_emails.collect { |contact_email| contact_email.contact.company_name }.uniq
Performance could be a consideration for large sets, so you might need to use a more sophisticated SQL query if that's an issue.
EDIT to answer your 2nd question
If company_name is a column, you can do:
ContactEmail.count(:all, :joins => :contact, :group => 'contact.company_name')
On a virtual attribute I think you'd have to retrieve the whole set and use Ruby (untested):
ContactEmail.find(:all, :joins => :contact, :select => 'contacts.company_name').group_by(&:company_name).inject({}) {|hash,result_set| hash.merge(result_set.first=>result_set.last.count)}
but that's not very kind to the next person assigned to maintain your system -- so you're better off working out the query syntax for the .count version and referring to the column itself.