I'm using the PublicActivity gem: https://github.com/pokonski/public_activity
All of the models I use PublicActivity to track use the column edition_id. And I'm wondering how I can scope by that column since it's polymorphic relation.
Eg PublicActivity looks like so:
PublicActivity::Activity.limit(50)
+----+--------------+----------------+----------+------------+--------------------+------------+--------------+----------------+---------------------------+---------------------------+
| id | trackable_id | trackable_type | owner_id | owner_type | key | parameters | recipient_id | recipient_type | created_at | updated_at |
+----+--------------+----------------+----------+------------+--------------------+------------+--------------+----------------+---------------------------+---------------------------+
| 1 | 42 | QuizMaster | 6 | User | quiz_master.update | {} | | | 2013-04-12 17:33:14 +0100 | 2013-04-12 17:33:14 +0100 |
| 2 | 25 | Place | 6 | User | place.update | {} | | | 2013-04-12 17:42:42 +0100 | 2013-04-12 17:42:42 +0100 |
| 3 | 25 | Event | 6 | User | event.update | {} | | | 2013-04-12 17:45:08 +0100 | 2013-04-12 17:45:08 +0100 |
| 4 | 20 | QuizMaster | 6 | User | quiz_master.update | {} | | | 2013-04-12 17:49:09 +0100 | 2013-04-12 17:49:09 +0100 |
| 5 | 20 | QuizMaster | 6 | User | quiz_master.update | {} | | | 2013-04-12 17:50:51 +0100 | 2013-04-12 17:50:51 +0100 |
+----+--------------+----------------+----------+------------+--------------------+------------+--------------+----------------+---------------------------+---------------------------+
Where edition_id is on the polymorphic trackable relation.
What I would like to do it something like:
PublicActivity::Activity.limit(50).includes(:trackable)# where trackable edition = 1
I'm not sure how or even if it's possible to join or include or preload a polymorphic model across multiple "trackable" types.
I don't think this is possible directly with SQL because of the polymorphism, but you could do something with ruby pretty easily.
PublicActivity::Activity.limit(50).select {|c| c.trackable.edition_id = 1 }
It won't be as efficient as a SQL query but using Rails preload it'll probably be good enough depending on the number of records you're fetching.
PublicActivity::Activity.limit(50).preload(:trackable).select {|c| c.trackable.edition_id = 1 }
I populate book items into my Book model,
But I found there are many items have the same id.
So, how to create unique id for items. To prevent many items from having the same id ?
Here is the book model code
# encoding: utf-8
class Book < ActiveRecord::Base
attr_accessible :name, :isbn ,:price ,:comment ,:author ,:sale_type ,:publisher ,:sn ,:category
attr_accessible :location, :category, :release_date
validates_uniqueness_of :sn
Here are the part of my items
irb(main):058:0> Book.all[1..10]
+-----+------+-----+-----+------+------+-----+------+-----+-----+------+------+-----+------+
| id | pric | com | cre | upda | rele | loc | sn | isb | aut | sale | name | cat | publ |
+-----+------+-----+-----+------+------+-----+------+-----+-----+------+------+-----+------+
| 118 | 4543 | 作 | 201 | 2013 | 2006 | --- | 2124 | 978 | 趙 | prom | 求索 | 商 | 聯經 |
| 118 | 872 | 馬 | 201 | 2013 | 2013 | --- | 2124 | 978 | 黎 | prom | 告別 | 政 | 聯經 |
| 118 | 2105 | 某 | 201 | 2013 | 2012 | --- | 2124 | 978 | 吳 | prom | 複眼 | 政 | 夏日 |
| 118 | 301 | 作 | 201 | 2013 | 2006 | --- | 2124 | 978 | 王 | norm | 天香 | 歷 | 麥田 |
| 118 | 411 | 少 | 201 | 2013 | 2008 | --- | 2124 | 978 | 韓 | norm | 鞋癖 | 商 | 聯經 |
| 119 | 3751 | 有 | 201 | 2013 | 2010 | --- | 2124 | 978 | 紀 | prom | 私家 | 體 | 印刻 |
| 119 | 3361 | 文 | 201 | 2013 | 2010 | --- | 2124 | 978 | 林 | fix_ | 我不 | 體 | 印刻 |
| 119 | 1140 | 何 | 201 | 2013 | 2012 | --- | 2124 | 978 | 邁 | norm | 正義 | 體 | 雅言 |
| 119 | 888 | 一 | 201 | 2013 | 2007 | --- | 2124 | 978 | 福 | fix_ | 生命 | 商 | 究竟 |
| 119 | 3283 | 近 | 201 | 2013 | 2011 | --- | 2124 | 978 | 芮 | norm | 海拉 | 政 | 遠流 |
+-----+------+-----+-----+------+------+-----+------+-----+-----+------+------+-----+------+
here the rake code to generate my data
16 bk = Book.new(:sn => real_sn,:name => book_name, :isbn=>isbn,
17 :price =>Random.rand(200..5000), :location=>location, :category=>["商業","歷史","體育","政治"].sample,
18 :author => author, :sale_type => [:fix_priced, :normal, :promotion].sample, :publisher => publisher,
19 :release_date => rand(10.years).ago, :comment => comment
20 )
Columns in the table I use the Postgre DB
Column | Type | Modifiers
--------------+-----------------------------+----------------------------------------------------
id | integer | not null default nextval('books_id_seq'::regclass)
price | integer |
comment | text |
created_at | timestamp without time zone | not null
updated_at | timestamp without time zone | not null
release_date | text |
location | text |
sn | bigint |
isbn | bigint |
author | text |
sale_type | text |
name | text |
category | text |
publisher | text |
Indexes:
"books_pkey" PRIMARY KEY, btree (id)
The code above, does not save any record in the database, it just instantiate objects of Book model. You should either save the object after initialization bk.save or use the create method instead of new.
bk = Book.new(:sn => real_sn,:name => book_name, :isbn=>isbn,
:price =>Random.rand(200..5000), :location=>location,
:category=>["商業","歷史","體育","政治"].sample, :author => author,
:sale_type => [:fix_priced, :normal, :promotion].sample,
:publisher => publisher, :release_date => rand(10.years).ago,
:comment => comment)
bk.save
Or alternatively you can use the create method
bk = Book.create(:sn => real_sn,:name => book_name, :isbn=>isbn,
:price =>Random.rand(200..5000), :location=>location,
:category=>["商業","歷史","體育","政治"].sample, :author => author,
:sale_type => [:fix_priced, :normal, :promotion].sample,
:publisher => publisher, :release_date => rand(10.years).ago,
:comment => comment)
Once saved in the database, it will automatically gain a unique id.
I have such db table structure:
id | currency_list_id | direction_id | value | updated_at
and i have such data:
1 | 1 | 1 | 8150 | 09-08-2010 01:00:00
1 | 1 | 2 | 8250 | 09-08-2010 01:00:00
1 | 2 | 1 | 8150 | 06-08-2010 01:00:00
1 | 2 | 2 | 8150 | 06-08-2010 01:00:00
1 | 1 | 1 | 8150 | 09-08-2010 15:00:00
1 | 1 | 2 | 8250 | 09-08-2010 15:00:00
so currency in exchanger is setted almost everyday, and could be setted more than one time in a day.... but also one could be setted some days ago... And i must to fetch all actual data..
How in rails (ruby) i could fetch only last actual data?
In my example result will be:
1 | 2 | 1 | 8150 | 06-08-2010 01:00:00
1 | 2 | 2 | 8150 | 06-08-2010 01:00:00
1 | 1 | 1 | 8150 | 09-08-2010 15:00:00
1 | 1 | 2 | 8250 | 09-08-2010 15:00:00
how to do this?
i try so:
#currencies = CurrencyValue.find(:all, :conditions => {:currency_list_id => id}, :order => :updated_at)
but then i will fetch all data for some currency_list_id with ordering, but how to fetch only last 2 values? How to fetch last 2 ordered rows?
#currencies = CurrencyValue.find(:all, :conditions => {:currency_list_id => id, :order => :updated_at}).last(2)
I think :). Can't check this right now.
I think what you need by be a GROUP_BY. There's another question that explains it here:
How to get the latest record in each group using GROUP BY?
I'm using rails 3 and I can't seem to check if a given instance is in a scope, see here:
p = Post.find 6
+----+----------+-------------------------+-------------------------+-------------------------+-----------+
| id | title | publish_date | created_at | updated_at | published |
+----+----------+-------------------------+-------------------------+-------------------------+-----------+
| 6 | asfdfdsa | 2010-03-28 22:33:00 UTC | 2010-03-28 22:33:46 UTC | 2010-03-28 22:33:46 UTC | true |
+----+----------+-------------------------+-------------------------+-------------------------+-----------+
I have a menu scope which looks like:
scope :menu, where("published != ?", false).limit(4)
When I run it I get:
Post.menu.all
+----+------------------+------------------+------------------+-------------------+-----------+
| id | title | publish_date | created_at | updated_at | published |
+----+------------------+------------------+------------------+-------------------+-----------+
| 1 | Lorem ipsum | 2010-03-23 07... | 2010-03-23 07... | 2010-03-28 21:... | true |
| 2 | fdasf | 2010-03-28 21... | 2010-03-28 21... | 2010-03-28 21:... | true |
| 3 | Ruby’s Imple... | 2010-03-28 21... | 2010-03-28 21... | 2010-03-28 21:... | true |
| 4 | dsaD | 2010-03-28 22... | 2010-03-28 22... | 2010-03-28 22:... | true |
+----+------------------+------------------+------------------+-------------------+-----------+
Which is correct, but if I try to check if p is in the the menu scope using: Post.menu.exists?(p) I get true when it should be false
What is the proper way to find out if a given instance of something is in a scope?
Actually, I was able to solve it using that Array method of include? instead of exists?
I have complex form similar to a recent Ryan Bates screencast
The nested elements work fine however. I'm creating or updating a grid of data such as this through a form where the day's prices are the input. My problem begins when they leave one blank. I have the nested_attributes_for option for not saving nils and it works, if they only save one value in a particular row, it saves the correct day however when reloaded, it will place it in the wrong column. I'm not sure how to order the values in a row to the form. IE A saved value for wednesday will appear in the monday column (of the correct row). This doesn't happen if they save all value for a row (then it works perfectly).
Data is stored in the DB like so
ID OBJECT_ID DAYOFWEEK PRICE and displaying like below
+------+----------------+-------+-------+-------+------+-------+
| id | name | Mon | Tue | Wed | Thu | Fri | -> +2 more days etc
+------+----------------+-------+-------+-------+------+-------+
| 1234 | Some name | 87.20 | 87.20 | 87.20 | 82.55| 85.48 |
+------+----------------+-------+-------+-------+------+-------+
| 1234 | Some name | 87.20 | 87.20 | 87.20 | 82.55| 85.48 |
+------+----------------+-------+-------+-------+------+-------+
| 1234 | Some name | 87.20 | 87.20 | 87.20 | 82.55| 85.48 |
+------+----------------+-------+-------+-------+------+-------+
The controller code either building or display these values is like so:
controller
#rooms.each do |r|
((r.room_rates.size+1)..7).each {
r.room_rates.build
}
end
rooms.html.erb
<% #dow = 0 %>
<tr class="room">
<td><%= f.text_field :name %></td>
<% f.fields_for :room_rates do |rates| %>
<%= render 'rates', :f => rates %>
<% #dow += 1 %>
<% end %>
<td class="delete_mode" style="display:none;">
<%= f.hidden_field :_destroy %>
<%= link_to_function "remove", "remove_room(this)" %>
</td>
</tr>
rates.html.erb
<td>
<%= f.text_field :price, :size => 3 %>
<%= f.hidden_field :dayofweek, :value => #dow %>
<%= f.hidden_field :source, :value => 0 %>
</td>
room_rates model (where the data from the form is going)
+-------+---------+-----------+-------+--------+---------------------------+---------------------------+
| id | room_id | dayofweek | price | source | created_at | updated_at |
+-------+---------+-----------+-------+--------+---------------------------+---------------------------+
| 92745 | 8 | 0 | 1.0 | 0 | 2010-02-23 14:33:05 +0100 | 2010-02-23 14:33:05 +0100 |
| 92746 | 8 | 1 | 2.0 | 0 | 2010-02-23 14:33:05 +0100 | 2010-02-23 14:33:05 +0100 |
| 92747 | 8 | 2 | 3.0 | 0 | 2010-02-23 14:33:05 +0100 | 2010-02-23 14:33:05 +0100 |
| 92748 | 8 | 3 | 4.0 | 0 | 2010-02-23 14:33:05 +0100 | 2010-02-23 14:33:05 +0100 |
| 92749 | 8 | 4 | 5.0 | 0 | 2010-02-23 14:33:05 +0100 | 2010-02-23 14:33:05 +0100 |
| 92750 | 8 | 5 | 6.0 | 0 | 2010-02-23 14:33:05 +0100 | 2010-02-23 14:33:05 +0100 |
| 92751 | 8 | 6 | 7.0 | 0 | 2010-02-23 14:33:05 +0100 | 2010-02-23 14:33:05 +0100 |
| 92752 | 9 | 3 | 5.0 | 0 | 2010-02-23 14:33:33 +0100 | 2010-02-23 14:33:33 +0100 |
+-------+---------+-----------+-------+--------+---------------------------+---------------------------+
ordering in the console
+---------+-----------+-------+--------+---------------------------+---------------------------+
| room_id | dayofweek | price | source | created_at | updated_at |
+---------+-----------+-------+--------+---------------------------+---------------------------+
| 2517 | 0 | | | | |
| 2517 | 1 | | | | |
| 2517 | 2 | 3.0 | 0 | 2010-02-23 17:54:28 +0100 | 2010-02-23 17:54:28 +0100 |
| 2517 | 3 | 4.0 | 0 | 2010-02-23 17:54:28 +0100 | 2010-02-23 17:54:28 +0100 |
| 2517 | 4 | | | | |
| 2517 | 5 | | | | |
| 2517 | 6 | | | | |
+---------+-----------+-------+--------+---------------------------+---------------------------+
The error is when you create the form - because you are depending on the order of the room_rates to be correct, you need to put the empty (built) rates into the correct positions. If each room has many room rates, you need to generate the form so that the rates are at the right day in the week. This code will build that in a new array, and set the new array correctly:
#rooms.each do |r|
new_rates = []
(0..6).each { |dow|
rate = r.room_rates.find_by_dayofweek(dow)
if rate
new_rates << rate
else
new_rates << r.room_rates.build(:dayofweek => dow)
end
}
r.room_rates = new_rates
end
Alternatively, you may be able to just build the missing weeks, if you specify an order for your association:
// In room model
has_many :rates, :order => "dayofweek"
// In controller
#rooms.each do |r|
(0..6).each { |dow|
if not r.room_rates.find_by_dayofweek(dow)
r.room_rates.build(:dayofweek => dow)
end
}
end