I have a profile card of user that have registration in my forum.
Person.update_all({:name => params[:person][:name],
:sex => params[:person][:sex],
:age => params[:person][:age],
:avatar => params[:person][:avatar].original_filename,
:city => params[:person][:city]},
{:id => params[:id]})
This is query for updating data in database. But here is a small problem - this will work only in a situation, if I the user send through form avatar (image). If not send avatar - that means the user already have uploaded avatar and the form send only name, sex, age and city. So in this case I'll get error in line :avatar => params[:person][:avatar].original_filename, -- and I would like to ask you for, if exist some elegant way, how to treat this moment.
I thought something like this:
if params[:person][:avatar]
avatar = ':avatar => params[:person][:avatar].original_filename,'
end
Person.update_all({:name => params[:person][:name],
:sex => params[:person][:sex],
:age => params[:person][:age],
avatar
:city => params[:person][:city]},
{:id => params[:id]})
But unfortunately, this doesn't work... How you're solving similar situation?
Thank you.
Well, it seems, like your params[:person] keys are similar to your model fields. So why don't you just pass params[:person] to update_all?
Alternatively, you could create a hash person, initialize it the way you want and then pass it to update_all
person = { :name => params[:person][:name] ,
...
if params[:person][:avatar]
person[:avatar] = params[:person][:avatar].original_filename
end
Person.update(params[:id], person)
I've changed update_all to update, because update_all is used to update all the records (that match the condition), while update find's the record by it's ID.
But again, it's a bad practice and you have to type a lot of unnecessary code.
One more thing. update_all makes a direct DB call, which doesn't involve validations, callbacks etc.
So, if you don't have some special reason for this, you'd better do something like this:
#person = Person.find params[:id]
#person.update_attributes params[:person]
I really think, you should check this book out
Updated once again :)
You see, such things belong to your models, not controllers. You could define a setter in the model:
def avatar=(value)
write_attribute(:avatar, value.original_filename)
end
Related
I have the following code:
results = Report.where(:car => 'xxxx').group(:date, :name, :car).select('date, name ,car, info, MAX(price) AS max_price')
for customer in customers
result = results.where(:date => customer.date, :name => customer.name, :car => customer.car).first
.... rest of the code ....
end
I have a database with many records ~20,000, so I want to optimize the code and cache results in memory.
Once again: my overall intention is make this code more efficient in terms of time. I want it to run faster than it is now and I want to reduce amount of database calls.
I am thinking of making my inital results object an array. I have a remote database so each .where query takes sometime. When I make results an array by adding .to_a - I load it to memory. So I think, it should be better(but not really sure)
Something like:
results = Report.where(:car => 'xxxx').group(:date, :name, :car)
.select('date, name ,car, info, MAX(price) AS max_price')
.to_a
for customer in customers
result = results.select {|result| result.date == customer.date and result.name == customer.name and result.car == customer.car }
.first
end
Well, the best things to have an association to fetch all reports for customers. In the case when you can not do so, I would recommend making only one query instead of n+1(as stated in the question) like this:
results = Report.where(:car => 'xxxx').group(:date, :name, :car)
.select('date, name ,car, info, MAX(price) AS max_price')
.where(:date => customers.map(&:date), :name => customers.map(&:name), :car => customers.map(&:car))
Assuming customers is an array of objects which respond to :name, :car, and :date methods.
One thing that should be noted is it does not guarantee that it will fetch reports of an exact customer. For that, you'd have to verify it by iterating through the results object yourself.
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 am using Ruby v1.8 and Rails v2.3.
I have a two model objects: Cars and Customers,
Model Cars:
class car < ActiveRecord::Base
#car has attribute :town_code
has_many :customers
end
Model Customers:
class customer < ActiveRecord::Base
# customer has attribute :first_name, :last_name
belongs_to :car
end
Now in my controller, I got a string from VIEW, and the received string has the format firstname.lastname#town_code, for example a string like "John.smith#ac01" which can be parsed as first_name="John", last_name="smith" and town_code="ac01"
Now I would like use the Rails's way to query the database to find all the customer objects (match the above conditions) from Customers table which has :
first_name="John",
last_name="smith"
and owned a car(by car_id) with car's town_code="ac01".
what is Rails' syntax to query this?
I know it should be something like (if I wanna count the nr of matched customer):
Customer.count :consitions =>{:first_name => "John", :last_name=>"smith"...}
But, I am not sure how to refer to a customer that has a referenced car with car's town_code= "ac01" ?
------------------ My question --------------------
I want to have two queries:
-one is used to count the number of matching customers,
-the other query returns the customers objects like find_by_ query.
What is the syntax in Ruby on Rails for the two queries?
It should be something similar to
Customer.where(:firstname => "John", :last_name => "Smith").count
If you have many Customers of Car, you can do something like
Car.where(...).customers.where(...)
You should really be firing rails c to test your queries in (I might be slightly off)
You could have something like:
#customers = car.where(:town_code => town_code).customers.where(:first_name => first_name, :last_name => last_name)
And then just count the results:
#customer_count = #customers.count
This assuming you parsed your string into the variables town_code, first_name, and last_name, like you said.
Edit
I don't think Rails v2.3 supports these chains of Active Record queries because I believe it lacks lazy loading from DB. I'm not completely sure. Also, I realize my first suggestion would't work because there could be many cars with the same town_code. I guess you could solve it using the map function like so (not tested):
#customers = car.all(:conditions => {:town_code => town_code}).map{ |c| c.customers.where(:first_name => first_name, :last_name => last_name) }
And then count them like before:
#customer_count = #customers.count
I believe you could do something like this: source
Customer.find(:all, :include => :car, :conditions => "customers.first_name = 'John' AND customers.last_name = 'Smith' AND cars.town_code = 'ac01'")
Counting all customers with a specification can be achieved by this command: source
Customer.count(:all, :include => :car, :conditions => "customers.first_name = 'John' AND customers.last_name = 'Smith' AND cars.town_code = 'ac01'")
By the way, if you are in the position to choose what you work with, I would advise you to go for Rails 3. The chaining methods described by Joseph would make this kind of query a lot easier and it'll save you upgrading issues down the road. (And you tagged the question for Rails 3)
I have a relationship table in a rails application called edit_privileges, in which the User is the "editor" and a number of other classes are "editable". Let's say that two of those classes are Message and Comment.
My EditPrivilege model uses the following code:
belongs_to :editor, :class_name => "User"
belongs_to :editable, :polymorphic => true
And User, of course
has_many :edit_privileges, :foreign_key => "editor_id"
In order to determine if a user has edit privileges for a certain model, I can't do the normal query:
user.edit_privileges.find_by_editable_id(#message.id)
because if the user has edit privileges to edit a comment with the same id as #message, the query will return true with the wrong edit privilege record from the table.
So, I tried doing these options:
user.edit_privileges.find(:all, :conditions => ["editable_id = ? AND editable_type ?", #message.id, #message.class.to_s])
user.edit_privileges.where(:editable_id => #message.id, :editable_type => #message.class.to_s)
which works great at finding the right record, but returns an array instead of an object (an empty array [] if there is no edit privilege). This is especially problematic if I'm trying to create a method to destroy edit privileges, since you can't pass .destroy on an array.
I figure appending .first to the two above solutions returns the first object and nil if the result of the query is an empty has, but is that really the best way to do it? Are there any problems with doing it this way? (like, instead of using dynamic attribute-based finders like find_by_editabe_id_and_editable_type)
Use find(:first, ...) instead of find(:all, ...) to get one record (note it might return nil while find will raise an RecordNotFound exception). So for your example:
user.edit_privileges.find(:first, :conditions => { :editable_id => #message.id, :editable_type => #message.class.to_s })
BTW, if you're on more edge rails version (3.x), Model.where(...).first is the new syntax:
user.edit_privileges.where(:editable_id => #message.id, :editable_type => #message.class.to_s).first
So in my app I have notifications and different record counts that are used in the overall layout, and are therefore needed on every page.
Currently in my application_controller I have a lot of things like such:
#status_al = Status.find_by_name("Alive")
#status_de = Status.find_by_name("Dead")
#status_sus = Status.find_by_name("Suspended")
#status_hid = Status.find_by_name("Hidden")
#status_arc = Status.find_by_name("Archived")
#balloon_active = Post.where(:user_id => current_user.id, :status_id => #status_al.id )
#balloon_dependent = Post.where(:user_id => current_user.id, :status_id => #status_de.id )
#balloon_upcoming = Post.where(:user_id => current_user.id, :status_id => #status_sus.id )
#balloon_deferred = Post.where(:user_id => current_user.id, :status_id => #status_hid.id )
#balloon_complete = Post.where(:user_id => current_user.id, :status_id => #status_arc.id )
..
Thats really just a small piece, I have at least double this with similar calls. The issue is I need these numbers pretty much on every page, but I feel like I'm htting the DB wayyyy too many times here.
Any ideas for a better implementation?
Scopes
First off, you should move many of these into scopes, which will allow you to use them in far more flexible ways, such as chaining queries using ActiveRecord. See http://edgerails.info/articles/what-s-new-in-edge-rails/2010/02/23/the-skinny-on-scopes-formerly-named-scope/index.html.
Indexes
Second, if you're doing all these queries anyway, make sure you index your database to, for example, find Status quickly by name. A sample migration to accomplish the first index:
add_index :status (or the name of your Status controller), :name
Session
If the data you need here is not critical, i.e. you don't need to rely on it to further calculations or database updates, you could consider storing some of this data in the user's session. If you do so, you can simply read whatever you need from the session in the future instead of hitting your db on every page load.
If this data is critical and/or it must be updated to the second, then avoid this option.
Counter Caching
If you need certain record counts on a regular basis, consider setting up a counter_cache. Basically, in your models, you do the following:
Parent.rb
has_many :children
Child.rb
belongs_to :parent, :counter_cache => true
Ensure your parent table has a field called child_count and Rails will update this field for you on every child's creation/deletion. If you use counter_caching, you will avoid hitting the database to get the counts.
Note: Using counter_caching will result in a slightly longer create and destroy action, but if you are using these counts often, it's usually worth going with counter_cache.
You should only need 1 database query for this, something like:
#posts = Post.where(:user_id => current_user.id).includes(:status)
Then use Enumerable#group_by to collect the posts into the different categories:
posts_by_status = #posts.group_by do {|post| post.status.name }
which will give you a hash:
{'Alive' => [...], 'Dead' => [...]}
etc.