I'm using Ruby on Rails and I'm storing business hours like this:
CREATE TABLE "business_hours" (
"id" integer NOT NULL PRIMARY KEY,
"business_id" integer NOT NULL FOREIGN KEY REFERENCES "businesses",
"day" integer NOT NULL,
"open_time" time,
"close_time" time)
(which came from the thread at:
Storing Business Hours in a Database )
Now I want to pull the hours out for each day of the week and display them, and I'm trying to find the best (or at least a good) way.
Should I just have a helper method that loops through getting the days (from 0..6) for a given business_id and assign it to a variable for the associated day? I feel like there must be a better way -- with an array, or something, but it's hurting my head thinking about it, because I also have a form of 'select's where any of the hours for a given business can be updated at once.
Thanks for any guidance!
Use the enum column plugin to declare the day field as a enum field.
class BusinessHours < ActiveRecord::Migration
def self.up
create_table :business_hours do |t|
t.integer :business_id, :null => false
t.enum :day, :limit =>[:sun, :mon, :tue, :wed, :thu, :fri, :sat], :nill => false
t.time :open_time, :null => false
t.time :close_time, :null => false
end
end
def self.down
drop_table :business_hours
end
end
Now when you do find on the BusinessHour model you will get the day as a string.
b = BusinessHour.find_by_business_id(2).first
p b.day.to_s.camelize #prints Sun/Mon/Tue etc.
You can use the enum_select and enum_radio form helpers to create list box/radio button group for the enum group:
Since the number of days in a week really is fixed, you can join the table 6 times (plus the original) and do a query for a single row. I'd probably just do a single query and loop through the rows though.
Have you considered serializing the business hours? Using serialization you are essentially storing objects in the database.
class BusinessHour < ActiveRecord::Base
serialize :hours
...
end
BusinessHour.create :business => #business, :hours =>
{:mon => [mon_start_time, mon_end_time], :wed => [wed_start_time, wed_end_time],
...}
Personally I would go with the bitwise approach described in linked question. All you really need to do to make it work is write new accessor methods.
It would be easier to find the business and use the associations to retrieve the business_hours rows.
Try this in your view
<% #business.business_hours.each do |hrs| %>
<%= hrs.day_name %>: Open-<%= hrs.open_time %> Close-<%= hrs.close_time %>
<%- end -%>
In your business_hour.rb model file, create a default scope to make sure the days are always listed in order. You can also create the day_name method to make it easier to display the day.
default_scope :order => 'day ASC'
def day_name
case self.day
when 0 then "Sun"
when 1 then "Mon"
...
end
end
Related
I have the following table in my DB:
class CreateGoogleRecords < ActiveRecord::Migration
def change
create_table :google_records do |t|
t.string :user_id
t.string :date
t.text :stats
t.string :account_name
t.integer :total_conversions
t.decimal :total_cost
t.timestamps
end
end
end
I'm looking to create a table inside a view that groups together records by month (I can't use "date created because sometimes they are scraped in bulk from an API).
There is a lot of legacy code involved so rather than convert the column to datetime I was hoping I could convert the date string to a datetime object when performing the query.
I've tried writing a scope like:
scope :stats_for_reports, ->(start_date, end_date, user_ids) { select('user_id, sum(total_cost) as total_cost, sum(total_conversions) as total_conversions')
.where('date >= ? and date <= ?', start_date, end_date)
.where(user_id: user_ids)
.group(DateTime.parse(:date).month.to_s)}
but I receive a TypeError: can't convert Symbol into String error.
In the console I've been trying things like:
GoogleRecord.where(date: date_start..date_end).group{ |m| DateTime.parse(m.date).month }
or
GoogleRecord.where(date: date_start..date_end).group(:date).to_date
Am I on the right track with any of these?
Have you considered using ActiveRecord before_save, after_save, after_initialize? You may be able to create a DateWrapper (very similar to the EncryptionWrapper below) and convert the string to a date transparent to the rest of the code.
http://api.rubyonrails.org/classes/ActiveRecord/Callbacks.html
I am trying to populate a new table from an existing database but my method does not seem to be working properly. Below is my code.
class CreateEmployees < ActiveRecord::Migration
def change
create_table :employees do |t|
t.string :first_name, null: false
t.string :last_name, null: false
t.string :email, null: false
t.timestamps
end
Sale.find_each do |sale|
unless Employee.exists?(sale.employee)
puts "Employee #{sale.employee} created!"
else
puts "Employee #{sale.employee} already existed!"
end
employee_info = sale.employee.split
Employee.find_or_create_by(first_name: employee_info[0], last_name: employee_info[1], email:employee_info[2])
end
end
end
What I have is a main database called sales that with a field that contains employee. In that field you will find a string entry as so: "Mary Higgins higgins#korning.com".
Basically the sales database contains four distinct employees but the employees are listed many times. What I'm trying to do is to create four unique rows. I thought the code above would work but something seems to be off with my logic. When I run the above code it, goes through the n amount of rows and creates the Employee object so, essentially the unless statement never results to true for some reason. Could the problem lie in the .find_each method. Would a .each suffice? I don't know if any more information would need to be provided with my database but if its needed I'll supply more details.
sale.employee is a string eg "Mary Higgins higgins#korning.com"
exists? excepts a hash with the conditions like Employee.exists?(:email => "higgins#korning.com"). If you pass a string like you did, first, it converts the string to an integer then tries to find the record with that id which in your case will be 0 and because of that it always returns false.
I would change the find_each loop like this:
Sale.find_each do |sale|
employee_info = sale.employee.split
employee = Employee.find_or_create_by(first_name: employee_info[0], last_name: employee_info[1], email:employee_info[2])
if employee.new_record?
puts "Employee #{sale.employee} created!"
else
puts "Employee #{sale.employee} already existed!"
end
end
Let's say we have the following model.
create_table :meetings do |t|
t.datetime :started_at
t.datetime: ended_at
end
class Meeting < ActiveRecord::base
end
How would I order a meetings_result, so that the longest meeting is the first meeting in the collection and the shortest meeting the last.
Something like
Meeting.order(longest(started_at..ended_at))
Obviously that doesn't work.
How would I achieve this, preferably without using raw SQL?
I don't think you can do it without using raw SQL.
Using Raw SQL:
Meeting.order('(ended_at - start_at) DESC')
(works with PostGreSQL)
No SQL? Two options come to mind. Create an array of hashes and sort it there, or add another column in the db and sort on that.
# How many records in the meetings table? This array of hashes could get huge.
meetings_array = []
Meeting.all.each do |meeting|
meetings_array << {id: meeting.id, started_at: meeting.started_at, ended_at: meeting.ended_at , duration: meeting.ended_at - meeting.started_at }
end
meetings_array.sort_by { |hsh| hsh[:duration] }
Or, create another column:
# Is it worth adding another column?
create_table :meetings do |t|
t.datetime :started_at
t.datetime :ended_at
t.datetime :duration
end
Update this column whenever you have both started_at and ended_at. Then you can:
Meeting.order("duration")
I'm trying to write a migration and it looks something like this:
class AddStatusToWorks < ActiveRecord::Migration
def self.up
change_table :works do |t|
t.string :status
end
end
def self.down
change_table :works do |t|
t.remove :status
end
end
end
Thing is, I want to set different default values for "status" based on a boolean value that's already in the table, "complete." If complete = true, status = "complete." If not, status = "work in progress." (The reason I want a string instead of keeping complete as the boolean is because I want there to be able to be more than two possibilites for status.) Any idea how to do that? Do I just stick an if statement in there like this
change_table :works do |t|
t.string :status
if (:complete == true)
:value => "complete"
else
:value => "wip"
end
Er, so that doesn't look quite right. I googled a bit and found that you can set :default values, but that's not quite what I'm going for. Any ideas/help would be lovely. Thanks!
You don't need a default at all, you just need to add the new column and give it values. Something like this should work:
def self.up
change_table :works do |t|
t.string :status
end
Works.reset_column_information
Works.where(:complete => true).update_all(:status => 'complete')
Works.where(:complete => [false, nil]).update_all(:status => 'wip')
end
See the Migrations Guide for information on reset_column_information.
You could also do it straight in the database but you have to be careful about different boolean representations (PostgreSQL wants 't' and 'f', MySQL wants 1 and 0, SQLite wants 1 and 0 but Rails mistakenly uses 't' and 'f', ...):
t = connection.quote(true)
connection.execute(%Q{
update works
set status = case complete
when #{t} then 'complete'
else 'wip'
end
})
Remember that default values are created immediately when the record is created, and thus don't yet have values for fields w/o defaults. You'll likely want to move this sort of logic to your model. Perhaps in an ActiveRecord callback, i.e. before_validation or before_save.
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.)