Rails - Oct 2005 - Active Record: getting all tables from a database ?

hello

I have a problem which is not related to Ruby but I
want to use Ruby to solve it.

I have a database with more then 100 tables (Oracle).
I want to get all the tables from the database and
then I want to iterate over all of them to get the
attributes of the columns (especially the type of the
column).

I need this to automatically generate Data Access
Objects and Data Transfer Objects for C++. 

can this be done with Active Record ? there is
a Column Class but I do not know how to get all the
tables from the Database.


maybe someone can give me a hint.

regards

Markus




	

	
		
___________________________________________________________ 
Gesendet von Yahoo! Mail - Jetzt mit 1GB Speicher kostenlos - Hier anmelden:
http://mail.yahoo.de

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On Oct 29, 2005, at 11:10 AM, Markus Jais wrote:
> I have a database with more then 100 tables (Oracle).
> I want to get all the tables from the database and
> then I want to iterate over all of them to get the
> attributes of the columns (especially the type of the
> column).
>
> I need this to automatically generate Data Access
> Objects and Data Transfer Objects for C++.
>
> can this be done with Active Record ? there is
> a Column Class but I do not know how to get all the
> tables from the Database.
Yes. This is fun:

# Grab the table names from Oracle.
table_names = ActiveRecord::Base.connection.select_values(''select  
table_name from user_tables'')

# Create a model class for each table.
models = table_names.map do |table_name|
   # Class.new creates a subclass of AR::Base
   # table_name.camelize turns "foo_bar" into "FooBar"
   # const_set names the new class FooBar
   Object.const_set(table_name.camelize, Class.new(ActiveRecord::Base))
end

# Generate your DAOs for each model class.
puts "Generating DAOs"
models.each do |model
   puts "#{model.name}: #{model.column_names.join('',
'')}"
   generate_dao(model)
end

def generate_dao(model)
   model.columns.each do |column|
     # Work with column.type, etc.
   end
end

Best,
jeremy
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.2 (Darwin)

iD8DBQFDY9m4AQHALep9HFYRAryUAKDjXyg2JXwZqmt8Sp0yimozAgBQ4ACbBz+C
eMzewkaY/5STuIZ/N8U0/8U=ITQC
-----END PGP SIGNATURE-----

--- Jeremy Kemper <jeremy-w7CzD/W5Ocjk1uMJSBkQmQ@public.gmane.org>
schrieb:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> On Oct 29, 2005, at 11:10 AM, Markus Jais wrote:
> > I have a database with more then 100 tables
> (Oracle).
> > I want to get all the tables from the database and
> > then I want to iterate over all of them to get the
> > attributes of the columns (especially the type of
> the
> > column).
> >
> > I need this to automatically generate Data Access
> > Objects and Data Transfer Objects for C++.
> >
> > can this be done with Active Record ? there is
> > a Column Class but I do not know how to get all
> the
> > tables from the Database.
> 
> Yes. This is fun:
> 
> # Grab the table names from Oracle.
> table_names >
ActiveRecord::Base.connection.select_values(''select
> 
> table_name from user_tables'')
> 
> # Create a model class for each table.
> models = table_names.map do |table_name|
>    # Class.new creates a subclass of AR::Base
>    # table_name.camelize turns "foo_bar" into
> "FooBar"
>    # const_set names the new class FooBar
>    Object.const_set(table_name.camelize,
> Class.new(ActiveRecord::Base))
> end
> 
> # Generate your DAOs for each model class.
> puts "Generating DAOs"
> models.each do |model
>    puts "#{model.name}: #{model.column_names.join('',
> '')}"
>    generate_dao(model)
> end
> 
> def generate_dao(model)
>    model.columns.each do |column|
>      # Work with column.type, etc.
>    end
> end
> 
> Best,
> jeremy
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v1.4.2 (Darwin)
> 
hi Jeremy

thank you very much. this is what I was looking for.


Markus




	

	
		
___________________________________________________________ 
Gesendet von Yahoo! Mail - Jetzt mit 1GB Speicher kostenlos - Hier anmelden:
http://mail.yahoo.de