How to create "custom" fields in Model? like sum, based on quantity
and price.
I guess it should be something like:
def summ
price * quantity
end
Am I right?
If so, How to use them in :conditions parameter of the
ActiveRecord::Base::find method? Is it possible it all?
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if you want to do that, you''re gonna have to learn some SQL. open up your SQL browser/command line and try ===========================SELECT (price * quantity) FROM table_name; SELECT table_name.*, (price * quantity) FROM table_name; SELECT table_name.*, (price * quantity) AS total_price FROM table_name; SELECT * FROM table_name WHERE (price * quantity) > 30.00; =========================== now go into ruby script/console ==========================object = Model.find(:first, :select => "(price * quantity) AS total_price) object.total_price object = Model.find(:all, :conditions => "(price * quantity) > 30") ========================== hopefully that''ll give you a good start :) gneeot wrote:> How to create "custom" fields in Model? like sum, based on quantity > and price. > I guess it should be something like: > > def summ > price * quantity > end > Am I right? > > If so, How to use them in :conditions parameter of the > ActiveRecord::Base::find method? Is it possible it all?-- Posted via http://www.ruby-forum.com/. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
Thnak you Matthew, I know SQL a bit :), but what to do if field is
much more complicated, for ex. I have few more complex fields in my
Order model:
def number_of_produced_items
total = 0
productions.each do |p|
total += p.quantity if p.start_time and p.finish_time
end
total
end
def number_of_dispatched_items
total = 0
dispatches.each do |p|
total += p.quantity
end
total
end
def number_of_items_in_progress
total = 0
productions.each do |p|
total += p.quantity if not p.finish_time
end
total
end
def enough_items_to_be_dispatched?
if (number_of_produced_items > 0 and number_of_dispatched_items <
number_of_produced_items) then true else false end
end
,and don''t want to redefine them in every find method, it takes a lot
of time :)
for ex., one of these fields I redefined for one of the combo boxes as
quite long SQL:
select("dispatch", "order_id",
Order.find_by_sql("SELECT * FROM orders o WHERE id in
(
SELECT p.order_id FROM productions p
WHERE p.start_time is not NULL and p.finish_time is not NULL
GROUP BY p.order_id
HAVING sum(p.quantity) > IFNULL(
(
SELECT sum(d.quantity) FROM dispatches d
WHERE d.order_id = p.order_id
GROUP BY d.order_id
) ,0)
)
Does anyone have any Idea how to simplify it all?
--
Yuriy
On Jul 16, 12:22 pm, Matthew Rudy
<rails-mailing-l...-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org>
wrote:> if you want to do that, you''re gonna have to learn some SQL.
>
> open up your SQL browser/command line and try
> ===========================> SELECT (price * quantity) FROM table_name;
>
> SELECT table_name.*, (price * quantity) FROM table_name;
>
> SELECT table_name.*, (price * quantity) AS total_price FROM table_name;
>
> SELECT * FROM table_name WHERE (price * quantity) > 30.00;
> ===========================>
> now go into ruby script/console
>
> ==========================> object = Model.find(:first, :select =>
"(price * quantity) AS
> total_price)
> object.total_price
>
> object = Model.find(:all, :conditions => "(price * quantity) >
30")
> ==========================>
> hopefully that''ll give you a good start
>
> :)
>
> gneeot wrote:
> > How to create "custom" fields in Model? like sum, based on
quantity
> > and price.
> > I guess it should be something like:
>
> > def summ
> > price * quantity
> > end
> > Am I right?
>
> > If so, How to use them in :conditions parameter of the
> > ActiveRecord::Base::find method? Is it possible it all?
>
> --
> Posted viahttp://www.ruby-forum.com/.
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Yuriy, I think in certain cases it''s absolutely kosher to just add methods like you did. Just make sure it doesn''t create additional SQL select calls for you, for example, use :include => :productions when calling find for your model. Cheers, Yuri On 7/16/07, gneeot <YuraPadlyak-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:> > > Thnak you Matthew, I know SQL a bit :), but what to do if field is > much more complicated, for ex. I have few more complex fields in my > Order model: > > def number_of_produced_items > total = 0 > productions.each do |p| > total += p.quantity if p.start_time and > p.finish_time > end > total > end > > def number_of_dispatched_items > total = 0 > dispatches.each do |p| > total += p.quantity > end > total > end > > def number_of_items_in_progress > total = 0 > productions.each do |p| > total += p.quantity if not p.finish_time > end > total > end > > def enough_items_to_be_dispatched? > if (number_of_produced_items > 0 and number_of_dispatched_items > < > number_of_produced_items) then true else false end > end > > ,and don''t want to redefine them in every find method, it takes a lot > of time :) > > for ex., one of these fields I redefined for one of the combo boxes as > quite long SQL: > > select("dispatch", "order_id", > Order.find_by_sql("SELECT * FROM orders o WHERE id in > ( > SELECT p.order_id FROM productions p > WHERE p.start_time is not NULL and p.finish_time is not NULL > GROUP BY p.order_id > HAVING sum(p.quantity) > IFNULL( > ( > SELECT sum(d.quantity) FROM dispatches d > WHERE d.order_id = p.order_id > GROUP BY d.order_id > ) ,0) > ) > > Does anyone have any Idea how to simplify it all? > > -- > Yuriy > > On Jul 16, 12:22 pm, Matthew Rudy <rails-mailing-l...-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org> > wrote: > > if you want to do that, you''re gonna have to learn some SQL. > > > > open up your SQL browser/command line and try > > ===========================> > SELECT (price * quantity) FROM table_name; > > > > SELECT table_name.*, (price * quantity) FROM table_name; > > > > SELECT table_name.*, (price * quantity) AS total_price FROM table_name; > > > > SELECT * FROM table_name WHERE (price * quantity) > 30.00; > > ===========================> > > > now go into ruby script/console > > > > ==========================> > object = Model.find(:first, :select => "(price * quantity) AS > > total_price) > > object.total_price > > > > object = Model.find(:all, :conditions => "(price * quantity) > 30") > > ==========================> > > > hopefully that''ll give you a good start > > > > :) > > > > gneeot wrote: > > > How to create "custom" fields in Model? like sum, based on quantity > > > and price. > > > I guess it should be something like: > > > > > def summ > > > price * quantity > > > end > > > Am I right? > > > > > If so, How to use them in :conditions parameter of the > > > ActiveRecord::Base::find method? Is it possible it all? > > > > -- > > Posted viahttp://www.ruby-forum.com/. > > > > >-- Best regards, Yuri Leikind --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
Hi It depends on the size of the related record set (productions). Looping through a huge recordset will probably be less performant (and more cpu and memory intensive) than using SQL to get what you want. However, don''t look for problems and bottlenecks as long as they''re not there. Switching these methods in your model to an SQL query instead of what you have now should be a trivial task, so if there''s ever a need to increase performance, it will be the time to look at other options such as an SQL query. For now, this is probably just fine. On 16 Jul 2007, at 16:59, Yuri Leikind wrote:> I think in certain cases it''s absolutely kosher to just add methods > like you did. Just make sure it doesn''t create additional SQL > select calls for you, for example, use :include => :productions > when calling find for your model. > > Cheers, > Yuri > > On 7/16/07, gneeot <YuraPadlyak-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote: > > Thnak you Matthew, I know SQL a bit :), but what to do if field is > much more complicated, for ex. I have few more complex fields in my > Order model: > > def number_of_produced_items > total = 0 > productions.each do |p| > total += p.quantity if p.start_time and > p.finish_time > end > total > end > > def number_of_dispatched_items > total = 0 > dispatches.each do |p| > total += p.quantity > end > total > end > > def number_of_items_in_progress > total = 0 > productions.each do |p| > total += p.quantity if not p.finish_time > end > total > end > > def enough_items_to_be_dispatched? > if (number_of_produced_items > 0 and > number_of_dispatched_items < > number_of_produced_items) then true else false end > endBest regards Peter De Berdt --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
Thank you. I think :include is what I''ve been missing sometimes. Will consider rewriting some staff to SQL. Regards, Yuriy On Jul 16, 6:17 pm, Peter De Berdt <peter.de.be...-LPO8gxj9N8aZIoH1IeqzKA@public.gmane.org> wrote:> Hi > > It depends on the size of the related record set (productions). > Looping through a huge recordset will probably be less performant > (and more cpu and memory intensive) than using SQL to get what you > want. However, don''t look for problems and bottlenecks as long as > they''re not there. Switching these methods in your model to an SQL > query instead of what you have now should be a trivial task, so if > there''s ever a need to increase performance, it will be the time to > look at other options such as an SQL query. For now, this is probably > just fine. > > On 16 Jul 2007, at 16:59, Yuri Leikind wrote: > > > > > I think in certain cases it''s absolutely kosher to just add methods > > like you did. Just make sure it doesn''t create additional SQL > > select calls for you, for example, use :include => :productions > > when calling find for your model. > > > Cheers, > > Yuri > > > On 7/16/07, gneeot <YuraPadl...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote: > > > Thnak you Matthew, I know SQL a bit :), but what to do if field is > > much more complicated, for ex. I have few more complex fields in my > > Order model: > > > def number_of_produced_items > > total = 0 > > productions.each do |p| > > total += p.quantity if p.start_time and > > p.finish_time > > end > > total > > end > > > def number_of_dispatched_items > > total = 0 > > dispatches.each do |p| > > total += p.quantity > > end > > total > > end > > > def number_of_items_in_progress > > total = 0 > > productions.each do |p| > > total += p.quantity if not p.finish_time > > end > > total > > end > > > def enough_items_to_be_dispatched? > > if (number_of_produced_items > 0 and > > number_of_dispatched_items < > > number_of_produced_items) then true else false end > > end > > Best regards > > Peter De Berdt--~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
Looks like :find only constructs SQL. I''m wondering is It possible to rewrite some of fields in my model using SQL, e.g. "number_of_items_in_progress" and then use them in :find? On Jul 18, 10:33 am, gneeot <YuraPadl...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:> Thank you. I think :include is what I''ve been missing sometimes. Will > consider rewriting some staff to SQL. > > Regards, > Yuriy > > On Jul 16, 6:17 pm, Peter De Berdt <peter.de.be...-LPO8gxj9N8aZIoH1IeqzKA@public.gmane.org> wrote: > > > Hi > > > It depends on the size of the related record set (productions). > > Looping through a huge recordset will probably be less performant > > (and more cpu and memory intensive) than using SQL to get what you > > want. However, don''t look for problems and bottlenecks as long as > > they''re not there. Switching these methods in your model to an SQL > > query instead of what you have now should be a trivial task, so if > > there''s ever a need to increase performance, it will be the time to > > look at other options such as an SQL query. For now, this is probably > > just fine. > > > On 16 Jul 2007, at 16:59, Yuri Leikind wrote: > > > > I think in certain cases it''s absolutely kosher to just add methods > > > like you did. Just make sure it doesn''t create additional SQL > > > select calls for you, for example, use :include => :productions > > > when calling find for your model. > > > > Cheers, > > > Yuri > > > > On 7/16/07, gneeot <YuraPadl...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote: > > > > Thnak you Matthew, I know SQL a bit :), but what to do iffieldis > > > much more complicated, for ex. I have few more complex fields in my > > > Order model: > > > > def number_of_produced_items > > > total = 0 > > > productions.each do |p| > > > total += p.quantity if p.start_time and > > > p.finish_time > > > end > > > total > > > end > > > > def number_of_dispatched_items > > > total = 0 > > > dispatches.each do |p| > > > total += p.quantity > > > end > > > total > > > end > > > > def number_of_items_in_progress > > > total = 0 > > > productions.each do |p| > > > total += p.quantity if not p.finish_time > > > end > > > total > > > end > > > > def enough_items_to_be_dispatched? > > > if (number_of_produced_items > 0 and > > > number_of_dispatched_items < > > > number_of_produced_items) then true else false end > > > end > > > Best regards > > > Peter De Berdt--~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
as I was saying before;
object = Model.find(:first, :select => "(price * quantity) AS
total_price)
you could refactor this
def self.find_with_total_price(*args)
self.with_scope(:find => {
:select => "*," + total_price_select
}) do
self.find(*args)
end
end
def total_price_select
"(price * quantity) AS total_price"
end
# make sure our reader method outputs an int
# else it''d just return a string
def total_price
read_attribute(:total_price).to_i
end
and do something similar for the rest.
gneeot wrote:> Looks like :find only constructs SQL. I''m wondering is It possible
to
> rewrite some of fields in my model using SQL, e.g.
> "number_of_items_in_progress" and then use them in :find?
--
Posted via http://www.ruby-forum.com/.
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