I have the following model
class Person
include Mongoid::Document
embeds_many :tasks
end
class Task
include Mongoid::Document
embedded_in :commit, :inverse_of => :tasks
field :name
end
How can I ensure the following?
person.tasks.create :name => "create facebook killer"
person.tasks.create :name => "create facebook killer"
person.tasks.count == 1
different_person.tasks.create :name => "create facebook killer"
person.tasks.count == 1
different_person.tasks.count == 1
i.e. task names are unique within a particular person
Having checked out the docs on indexes I thought the following might work:
class Person
include Mongoid::Document
embeds_many :tasks
index [
["tasks.name", Mongo::ASCENDING],
["_id", Mongo::ASCENDING]
], :unique => true
end
but
person.tasks.create :name => "create facebook killer"
person.tasks.create :name => "create facebook killer"
still produces a duplicate.
The index config shown above in Person would translate into for mongodb
db.things.ensureIndex({firstname : 1, 'tasks.name' : 1}, {unique : true})
Can't you just put a validator on the Task?
validates :name, :uniqueness => true
That should ensure uniqueness within parent document.
Indexes are not unique by default. If you look at the Mongo Docs on this, uniqueness is an extra flag.
I don't know the exact Mongoid translation, but you're looking for something like this:
db.things.ensureIndex({firstname : 1}, {unique : true, dropDups : true})
I don't believe this is possible with embedded documents. I ran into the same issue as you and the only workaround I found was to use a referenced document, instead of an embedded document and then create a compound index on the referenced document.
Obviously, a uniqueness validation isn't enough as it doesn't guard against race conditions. Another problem I faced with unique indexes was that mongoid's default behavior is to not raise any errors if validation passes and the database refuses to accept the document. I had to change the following configuration option in mongoid.yml:
persist_in_safe_mode: true
This is documented at http://mongoid.org/docs/installation/configuration.html
Finally, after making this change, the save/create methods will start throwing an error if the database refuses to store the document. So, you'll need something like this to be able to tell users about what happened:
alias_method :explosive_save, :save
def save
begin
explosive_save
rescue Exception => e
logger.warn("Unable to save record: #{self.to_yaml}. Error: #{e}")
errors[:base] << "Please correct the errors in your form"
false
end
end
Even this isn't really a great option because you're left guessing as to which fields really caused the error (and why). A better solution would be to look inside MongoidError and create a proper error message accordingly. The above suited my application, so I didn't go that far.
Add a validation check, comparing the count of array of embedded tasks' IDs, with the count of another array with unique IDs from the same.
validates_each :tasks do |record, attr, tasks|
ids = tasks.map { |t| t._id }
record.errors.add :tasks, "Cannot have the same task more than once." unless ids.count == ids.uniq.count
end
Worked for me.
You can define a validates_uniqueness_of on your Task model to ensure this, according to the Mongoid documentation at http://mongoid.org/docs/validation.html this validation applies to the scope of the parent document and should do what you want.
Your index technique should work too, but you have to generate the indexes before they brought into effect. With Rails you can do this with a rake task (in the current version of Mongoid its called db:mongoid:create_indexes). Note that you won't get errors when saving something that violates the index constraint because Mongoid (see http://mongoid.org/docs/persistence/safe_mode.html for more information).
You can also specify the index in your model class:
index({ 'firstname' => 1, 'tasks.name' => 1}, {unique : true, drop_dups: true })
and use the rake task
rake db:mongoid:create_indexes
you have to run :
db.things.ensureIndex({firstname : 1, 'tasks.name' : 1}, {unique : true})
directly on the database
You appear to including a "create index command" inside of your "active record"(i.e. class Person)
Related
I have a Rails App in which I want to use Thinking Sphinx for search. I have a has many though relationship between the following models, Product has many Types through ProductType.
# Product.rb
has_many :product_types
has_many :types, through: :product_types
# Type.rb
has_many :product_types
has_many :products, through: :product_types
# ProductType.rb
belongs_to :product
belongs_to :type
In my ProductsController index action I want to be able to filter which products are shown in the view based on given Variant ids.
My relevant indexes currently looks like this (note, I haven't used ThinkingSphinx in a long time):
# product_index.rb
ThinkingSphinx::Index.define :product, :with => :active_record do
indexes name, :sortable => true
indexes description
indexes brand.name, as: :brand, sortable: true
indexes product_types.type.id, as: :product_types
has created_at, updated_at
end
# type_index.rb
ThinkingSphinx::Index.define :type, :with => :active_record do
indexes name, :sortable => true
end
# product_type_index.rb
ThinkingSphinx::Index.define :product_type, :with => :active_record do
has product_id, type: :integer
has type_id, type: :integer
end
I currently pass an array of :product_types ids in a link_to, like this (let me know if there is a better way to do it):
= link_to "Web shop", products_path(product_types: Type.all.map(&:id), brand: Brand.all.map(&:id)), class: "nav-link"
In my ProductsController I try to filter the result based on the given Type ids like this:
product_types = params[:product_types]
#products = Product.search with_all: { product_types: product_types.collect(&:to_i) }
When I run rake ts:rebuild I get the following error:
indexing index 'product_type_core'...
ERROR: index 'product_type_core': No fields in schema - will not index
And when I tries to view the view in the browser I get the following error:
index product_core: no such filter attribute 'product_types'
- SELECT * FROM `product_core` WHERE `sphinx_deleted` = 0 AND
`product_types` = 1 AND `product_types` = 2 AND `product_types` = 3
LIMIT 0, 20; SHOW META
Any ideas in how to properly set up my indexes (and query) for this case?
There's a few issues to note here:
Firstly, the error you're seeing during rake ts:rebuild is pointing out that you've not set any fields in your ProductType Sphinx index - no indexes calls for text data you wish to search on. Are you actually searching on ProductType at all? If so, what text are you expecting people to match by?
If you're not searching on that model, there's no need to have a Sphinx index for it.
Secondly, the issue with your search - you're filtering on product_types with integers, which makes sense. However, in your index, you've defined product_types as a field (using indexes) rather than an attribute (using has). Given it's integer values and you're likely not expecting someone to type in an ID into a search input, you'll almost certainly want this to be an attribute instead - so change the indexes to a has for that line in your Product index definition, and run ts:rebuild.
Rails 4.2.5, Mongoid 5.1.0
I have three models - Mailbox, Communication, and Message.
mailbox.rb
class Mailbox
include Mongoid::Document
belongs_to :user
has_many :communications
end
communication.rb
class Communication
include Mongoid::Document
include Mongoid::Timestamps
include AASM
belongs_to :mailbox
has_and_belongs_to_many :messages, autosave: true
field :read_at, type: DateTime
field :box, type: String
field :touched_at, type: DateTime
field :import_thread_id, type: Integer
scope :inbox, -> { where(:box => 'inbox') }
end
message.rb
class Message
include Mongoid::Document
include Mongoid::Timestamps
attr_accessor :communication_id
has_and_belongs_to_many :communications, autosave: true
belongs_to :from_user, class_name: 'User'
belongs_to :to_user, class_name: 'User'
field :subject, type: String
field :body, type: String
field :sent_at, type: DateTime
end
I'm using the authentication gem devise, which gives access to the current_user helper, which points at the current user logged in.
I have built a query for a controller that satisfied the following conditions:
Get the current_user's mailbox, whose communication's are filtered by the box field, where box == 'inbox'.
It was constructed like this (and is working):
current_user.mailbox.communications.where(:box => 'inbox')
My issue arrises when I try to build upon this query. I wish to chain queries so that I only obtain messages whose last message is not from the current_user. I am aware of the .last method, which returns the most recent record. I have come up with the following query but cannot understand what would need to be adjusted in order to make it work:
current_user.mailbox.communications.where(:box => 'inbox').where(:messages.last.from_user => {'$ne' => current_user})
This query produces the following result:
undefined method 'from_user' for #<Origin::Key:0x007fd2295ff6d8>
I am currently able to accomplish this by doing the following, which I know is very inefficient and want to change immediately:
mb = current_user.mailbox.communications.inbox
comms = mb.reject {|c| c.messages.last.from_user == current_user}
I wish to move this logic from ruby to the actual database query. Thank you in advance to anyone who assists me with this, and please let me know if anymore information is helpful here.
Ok, so what's happening here is kind of messy, and has to do with how smart Mongoid is actually able to be when doing associations.
Specifically how queries are constructed when 'crossing' between two associations.
In the case of your first query:
current_user.mailbox.communications.where(:box => 'inbox')
That's cool with mongoid, because that actually just desugars into really 2 db calls:
Get the current mailbox for the user
Mongoid builds a criteria directly against the communication collection, with a where statement saying: use the mailbox id from item 1, and filter to box = inbox.
Now when we get to your next query,
current_user.mailbox.communications.where(:box => 'inbox').where(:messages.last.from_user => {'$ne' => current_user})
Is when Mongoid starts to be confused.
Here's the main issue: When you use 'where' you are querying the collection you are on. You won't cross associations.
What the where(:messages.last.from_user => {'$ne' => current_user}) is actually doing is not checking the messages association. What Mongoid is actually doing is searching the communication document for a property that would have a JSON path similar to: communication['messages']['last']['from_user'].
Now that you know why, you can get at what you want, but it's going to require a little more sweat than the equivalent ActiveRecord work.
Here's more of the way you can get at what you want:
user_id = current_user.id
communication_ids = current_user.mailbox.communications.where(:box => 'inbox').pluck(:_id)
# We're going to need to work around the fact there is no 'group by' in
# Mongoid, so there's really no way to get the 'last' entry in a set
messages_for_communications = Messages.where(:communications_ids => {"$in" => communications_ids}).pluck(
[:_id, :communications_ids, :from_user_id, :sent_at]
)
# Now that we've got a hash, we need to expand it per-communication,
# And we will throw out communications that don't involve the user
messages_with_communication_ids = messages_for_communications.flat_map do |mesg|
message_set = []
mesg["communications_ids"].each do |c_id|
if communication_ids.include?(c_id)
message_set << ({:id => mesg["_id"],
:communication_id => c_id,
:from_user => mesg["from_user_id"],
:sent_at => mesg["sent_at"]})
end
message_set
end
# Group by communication_id
grouped_messages = messages_with_communication_ids.group_by { |msg| mesg[:communication_id] }
communications_and_message_ids = {}
grouped_messages.each_pair do |k,v|
sorted_messages = v.sort_by { |msg| msg[:sent_at] }
if sorted_messages.last[:from_user] != user_id
communications_and_message_ids[k] = sorted_messages.last[:id]
end
end
# This is now a hash of {:communication_id => :last_message_id}
communications_and_message_ids
I'm not sure my code is 100% (you probably need to check the field names in the documents to make sure I'm searching through the right ones), but I think you get the general pattern.
I would like to seed my Products and assign them to a specific User and Store.
Product.rb
class Product < ActiveRecord::Base
belongs_to :user
belongs_to :store
def product_store=(id)
self.store_id = id
end
end
Note: Store belongs_to Business (:business_name)
Seed.rb
This is my basic setup:
user = User.create(:username => 'user', :email => 'user2#email.com')
store = Store.create(:business_name => 'store', :address => 'Japan')
I attempted these but they did not work:
# This gives random ID's ranging from 1 to 4425!?
user.products.create([{:name => "Apple", :product_store => Store.find_by_address('San Francisco, USA')}])
# This gives me undefined method 'walmart'.
user.store.products.create([ {:name => "Apple"} ])
Is there a way to set the ID's so I can associate my Products to a Store and User?
UPDATE -
I have tried the answers below and still came out unsuccessful. Does anyone know of another way to do this?
Although it sounds like you found a workaround, the solution may be of interested to others.
From your original seeds.rb
user = User.create(:username => 'user', :email => 'user2#email.com')
store = Store.create(:business_name => 'store', :address => 'Japan')
Create the store
Store.create({
user_id: user.id
store_id: store.id
}, without_protection: true)
In the original code snipped "user" and "store" variables are declared. The code assigns user_id / store_id (the model columns inferred by the belongs_to relationship in the Store model) to the id values that are present in the "user" and "store" variables.
"without_protection: true" turns off bulk assignment protection on the id fields. This is perfectly acceptable in a seeds file but should be used with extreme caution when dealing with user provided data.
Or alternatively create your stores.
Then extract the correct one
e.g.
store = Store.find_by_business_name('Test Store')
and then create it based on that
e.g.
store.products.create(:product_name => "Product Test", :price => '985.93')
This will then set the relationship id for you,
If I'm not mistaken, you're just trying to do this.
user = User.create(:username => 'usertwo', :email => 'user2#email.com')
walmart = Store.create(:business_name => 'Walmart', :address => 'San Francisco, USA')
user.products.create(:name => 'Apple', :store => walmart)
Anything else required here that I'm not seeing?
Try doing this
store_1 = Store.new(:business_name => 'Test Store',
:address => 'Test Address',
:phone_number => '555-555-555')
store_1.id = 1
store_1.save!
The trick is not to set the id within the hash as it is protected.
Scott
What I did was update the particular products to a certain user, see this question:
Can I update all of my products to a specific user when seeding?
You could just create a series of insert satements for this "seed migration", including the record Id for each user, store, product etc. You might have to update database sequences after this approach.
Another approach
Create the initial records in you Rails app, through the GUI / web.
Then use something like Yaml-db. So you can dump the data to a yaml file. You can now edit that file (if necessary) and use that same file to seed another instance of the db with "rake db:load"
Either way.... You know the Ids will not be shifting around on you when these objects are created in the new db instance.
I'm sure there are other ways to do this... Probably better ones, even.
Here is a link to a write-up I did a while back for using yaml_db to seed an oracle database
http://davidbharrison.com/database_seeding_oracle
Try this:
User.destroy_all
Product.destroy_all
user = User.create!([{:username => 'usertwo', :email =>'user2#email.com'},
{:username => 'userthree', :email => user3#email.com}])
user.each_with_index do |obj, index|
Product.create!([{ :product_name => 'product #{index}', :user_id => obj.id }])
end
The table would look like this:
Here's how I prefer to seed an association in rails 6
#teacher = Teacher.new(name: "John")
#student = #teacher.build_student(name: "Chris")
#teacher.save!
#student.save!
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 think it's safe to say everyone loves doing something like this in Rails:
Product.find(:all, :conditions => {:featured => true})
This will return all products where the attribute "featured" (which is a database column) is true. But let's say I have a method on Product like this:
def display_ready?
(self.photos.length > 0) && (File.exist?(self.file.path))
end
...and I want to find all products where that method returns true. I can think of several messy ways of doing it, but I think it's also safe to say we love Rails because most things are not messy.
I'd say it's a pretty common problem for me... I'd have to imagine that a good answer will help many people. Any non-messy ideas?
The only reliable way to filter these is the somewhat ugly method of retrieving all records and running them through a select:
display_ready_products = Product.all.select(&:display_ready?)
This is inefficient to the extreme especially if you have a large number of products which are probably not going to qualify.
The better way to do this is to have a counter cache for your photos, plus a flag set when your file is uploaded:
class Product < ActiveRecord::Base
has_many :photos
end
class Photo < ActiveRecord::Base
belongs_to :product, :counter_cache => true
end
You'll need to add a column to the Product table:
add_column :products, :photos_count, :default => 0
This will give you a column with the number of photos. There's a way to pre-populate these counters with the correct numbers at the start instead of zero, but there's no need to get into that here.
Add a column to record your file flag:
add_column :products, :file_exists, :boolean, :null => false, :default => false
Now trigger this when saving:
class Product < ActiveRecord::Base
before_save :assign_file_exists_flag
protected
def assign_file_exists_flag
self.file_exists = File.exist?(self.file.path)
end
end
Since these two attributes are rendered into database columns, you can now query on them directly:
Product.find(:all, :conditions => 'file_exists=1 AND photos_count>0')
You can clean that up by writing two named scopes that will encapsulate that behavior.
You need to do a two level select:
1) Select all possible rows from the database. This happens in the db.
2) Within Ruby, select the valid rows from all of the rows. Eg
possible_products = Product.find(:all, :conditions => {:featured => true})
products = possible_products.select{|p| p.display_ready?}
Added:
Or:
products = Product.find(:all, :conditions => {:featured => true}).select {|p|
p.display_ready?}
The second select is the select method of the Array object. Select is a very handy method, along with detect. (Detect comes from Enumerable and is mixed in with Array.)