Assuming that you have an existing application that you wish to rewrite in Rails, how would you prepare your database schema so that you can take advantage of the magick of db:migrate ?
Well, I had to do exactly that when I decided to rewrite an existing 200+tables CRM solution into e-CRM, a Rails application. This is what I did :-
a) Pluralize all the table names
Tip: One legacy table was named customer. To pluralize it to customers whilst retaing the data, I use CREATE TABLE customers SELECT * FROM customer for MySQL
b) Add an id field (auto-increment, integer) to every table
c) Add created_at, updated_at in every table to take advantage of Rails automatic updating of these fields without a single line of code
d) Added another magic column ie lock_version (must default to 0) to invoke optimistic locking
e) To support a belongs_to relationship, add belongs_to_tablename
f) Create a schema_info table with just 1 field ie Version, Integer and add a single record with the value=1
g) Use Rake db:schema:dump to create a schema.rb based on the underlying database schema . See following snapshot of Radrails in action
Well, I had to do exactly that when I decided to rewrite an existing 200+tables CRM solution into e-CRM, a Rails application. This is what I did :-
a) Pluralize all the table names
Tip: One legacy table was named customer. To pluralize it to customers whilst retaing the data, I use CREATE TABLE customers SELECT * FROM customer for MySQL
b) Add an id field (auto-increment, integer) to every table
c) Add created_at, updated_at in every table to take advantage of Rails automatic updating of these fields without a single line of code
d) Added another magic column ie lock_version (must default to 0) to invoke optimistic locking
e) To support a belongs_to relationship, add belongs_to_tablename
f) Create a schema_info table with just 1 field ie Version, Integer and add a single record with the value=1
g) Use Rake db:schema:dump to create a schema.rb based on the underlying database schema . See following snapshot of Radrails in action
That's it ! Updated on 4th November, 2007.
4 comments:
Cool article. I'll tag it for future reference.
I did alot of this automatically in
ruby scripts I wrote.
(Dbase/foxpro, and pervasive)
to rails.
http://mentalpagingspace.blogspot.com/2007/10/importing-from-odbc-sources-into-oracle.html
http://mentalpagingspace.blogspot.com/2007/10/import-and-cleanup-dbase-files-into.html
And automatically delete my basic controllers and models from the database, with rolerequirement,
and activescaffold
http://mentalpagingspace.blogspot.com/2007/10/production-generator-for-rails.html
By the way,
I'd recommend tabnav as well,
from seesaw. Unless your doing something more elaborate
Hi Glenn
Thanx for the compliments :-)
Looks as if you have managed to use RoR with dbf/fpt ?
Where can I get the dbf/fpt adpater for testing ?
Ok kimberly. Dbase is not "industrial" strength enough to support rails. So what you will find in my blog is a tool that will take a directory of "dbase" "independant" files and convert them all to a dbi sql database. In my case that is oracle (XE) or can be Mysql as well.
It adds the id fields automatically. And cleans up the fields names. It also makes sure the database names are plural, and create the rails sequence number field as well.
In addition "numeric" field names are "concatted" to a master table if they exist, the mastertable is in the command line as well.
Post a Comment