Here''s something that''s a snap to do in desktop database management systems (like Paradox or Access) but I haven''t figured out how to do it in RoR, and can''t seem to find any examples by googling, etc. My overall goal is to create a temporary space in which to create and process a single new record (representating a payment transaction), and when I''m done with it post it to the payments table. Some of the field values will be collected from the user and validated, then others will be calculated based on the user-supplied values and other factors. I don''t want to edit the payments table until I''m ready to post the completed record. In the desktop software, this would be done by creating an array based on the payment record''s column names, using that to gather and validate the data, then copying the array values into a new record. A single command can copytoarray or copyfromarray a record. I tried modelling this on the Cart example in Agile Web Development with Rails (which stores virtual lineitem records in the shopping cart). I was able to put a single empty record into @pmttrans, but couldn''t figure out how to address a field in that record in order to read or write a specific data value. The Cart example creates an @items array within @cart. Since I don''t need multiple items, how can I just create a simple hash of column names and values for the single record? Or is there an even simpler way to approach this that I''m missing? Thanks! Shauna -- 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 -~----------~----~----~----~------~----~------~--~---
do you mean like this (for a pointless example)?:
payment = Payment.new
payment.total = params[:total]
payment.tax = payment.total * 0.9
if payment.save
# Data is now save to database table
end
The point being that the table is only modified when you call the save
method when creating a new activeRecord object.
--~--~---------~--~----~------------~-------~--~----~
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
-~----------~----~----~----~------~----~------~--~---
Thanks. That''s the way I first tried it, but I''m concerned about two things. First, a transaction number is generated based on existing records in payment. What if another user tries to post a record to the same loan while the first user is taking their time with the first post? Also, is the payment table actually open when you execute Payment.new? I''d like to open it only if and when I''m ready to post. Or are these questions not relevant to a web-based app, and I need not worry about it? Shauna -- 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 -~----------~----~----~----~------~----~------~--~---
The table is not touched until you call save (and then only if the object validates).. So you generate a transaction number before receiving all the information from the user? Is this necessary? Could you give them the transaction number after it has been accepted? On Nov 29, 3:56 pm, Shauna <rails-mailing-l...-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org> wrote:> Thanks. That''s the way I first tried it, but I''m concerned about two > things. First, a transaction number is generated based on existing > records in payment. What if another user tries to post a record to the > same loan while the first user is taking their time with the first post? > Also, is the payment table actually open when you execute Payment.new? > I''d like to open it only if and when I''m ready to post. > > Or are these questions not relevant to a web-based app, and I need not > worry about it? > > Shauna > > -- > Posted viahttp://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 -~----------~----~----~----~------~----~------~--~---
Well, I''ve been trying to mimic the existing desktop app, where the number is presented first and then the user enters the date, selects the transaction code from a drop-down list, and fills in a few relevant fields which vary based on the transaction code they selected. It''s not always a simple consecutive number, because within a pay period there can be multiple decimalled transactions. But I''m just guessing that the user needs to verify this number before proceeding... I''ll ask the original developer. (Really I''d like to poll the existing users :) ) Thanks for the help. Shauna -- 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 -~----------~----~----~----~------~----~------~--~---
johnson_d-j9pdmedNgrk@public.gmane.org
2006-Nov-29 13:03 UTC
Re: How do I create an array to represent an empty record?
This is one of the classical breaking points of object-relational mapping - the transaction boundary. It occurs in single user and mutli-user paradigms equally. If, for auditing purposes, there is a requirement that transaction numbers be sequential, _and_ you don''t need a transaction number until the transaction is comitted, then generate your transaction ID at save time within the boundaries of the database transaction. If, for auditing purposes, there is a requirement that transaction numbers be sequential, _and_ you need transaction numbers early, then make sure that you record thetransactionearly, and be prepared to record the transaction as being canceled by user or aborted due to technical failure. If there is no need for keeping the transaction number sequential (not likely), then youcan throw away unused numbers. Numbers are cheap, if they have enough digits. --~--~---------~--~----~------------~-------~--~----~ 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 unknown (Guest), I know whereof you speak but the transaction number in this case is not a unique identifier in the payments table, it''s just unique within a particular loan. Although it''s a long shot that two different users might possibly be entering transactions for the same loan, I just wanted to be sure when and where I''d have to intervene if it did occur. The numbers do need to be sequential for human reasons (so that the order in which the transactions for a particular loan were entered is visually obvious when data is retrieved for reports etc.). Shauna -- 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 -~----------~----~----~----~------~----~------~--~---