From: Useko Netsumi <usenets@...>
Date: 2004-01-06T14:21:44+09:00
Subject: Re: Simple Ruby DB apps/programs ...

Ara.T.Howard wrote:
> On Mon, 5 Jan 2004, Useko Netsumi wrote:
> 
> 
>>Date: Mon, 05 Jan 2004 19:25:27 -0500
>>From: Useko Netsumi <usenets@yahoo.com>
>>Reply-To: usenets_remove_this@yahoo.com
>>Newsgroups: comp.lang.ruby
>>Subject: Re: Simple Ruby DB apps/programs ...
>>
>>Carl Youngblood wrote:
>>
>>>Useko Netsumi wrote:
>>>
>>>
>>>>I was wondering if there are some example of small Ruby(1.8.1) 
>>>>Database Apps/Programs. Preferably using Relational Database such as 
>>>>MySQL(4 or 5) or Oracle.
>>>>
>>>>I'd love to see some example of storing name(first,last), 
>>>>address(addr1,addr2,city,zip),phone(home,work,mobile), and a photo image.
>>>>
>>>>It took me a while to write it in PHP but perhaps I can do it in Ruby 
>>>>more cleanly while learning this great language.
>>>>
>>>>Thanks
>>>>
>>>>/useko
>>>>
>>>
>>>My favorite DBMS for small client apps is sqlite.  No other DB comes 
>>>close to it in terms of convenience and speed, as long as you're not 
>>>running a distributed type of an application with hundreds of clients 
>>>accessing the database at once.  There is no need for a database server 
>>>at all.  All necessary code for accessing the database is compiled in, 
>>>and databases are just plain old files.  And it is ACID-compliant. Check 
>>>out this ruby extension for it here:
>>>
>>>http://sqlite-ruby.sourceforge.net/
>>>
>>>Carl
>>>
>>
>>Thanks to all.
>>
>>Perhaps y'all can give me some advice. My apps are running a web photo 
>>apps with mutiple tables in the database. I do not store the image in 
>>the DB but just the /image/file/path and other textual information such 
>>as location, date, time, who took the pictures, and comment fields. 
>>User(s) can only browse, search, and list the information for now. And, 
>>I do not expect more than 20 users accessing it at any given time. Will 
>>it work with SQLITE? Or do I need MySQL or more advanced(more expensive) 
>>RDBMS to handle those tasks.
>>
>>Thanks
>>
>>/useko
>>
> 
> 
> i use pstore for alot of web stuff - it works fine:
> 
> ~/eg/ruby > cat photo.rb 
> require 'pstore'
> 
> class DB
>   def initialize path = 'photo.db'
>     @pstore = PStore.new path
>   end
>   def []= name, record 
>     address, phone = record
> 
>     @pstore.transaction do
>       @pstore[name] = [address, phone]
>     end
>   end
>   def [] name
>     @pstore.transaction(read_only = true){ @pstore[name] }
>   end
>   def each(&block)
>     @pstore.transaction do
>       @pstore.roots.each{|name| block.call(name, @pstore[name])}
>     end
>   end
>   def << record
>     first,last,addr1,addr2,city,zip,home,work,mobile = record
>     name    = Name[first, last]
>     address = Address[addr1,addr2,city,zip]
>     phone   = Phone[home,work,mobile]
>     self[name] = [address, phone]
>   end
> 
>   Name    = Struct.new "Name", :first, :last
>   Address = Struct.new "Address", :addr1, :addr2, :city, :zip
>   Phone   = Struct.new "Phone", :home, :work, :mobile
> 
>   [Name, Address, Phone].each{|c| class << c; alias [] new; end}
> end
> 
> if $0 == __FILE__
>   db = DB.new
> 
>   records = [
>     %w(john doe foo bar boulder 80304 1 2 3),
>     %w(jane doe bar foo boulder 80305 3 2 1),
>   ]
> 
>   records.each{|record| db << record}
> 
>   john = DB::Name['john', 'doe']
>   jane = DB::Name['jane', 'doe']
> 
>   db.each do |name, address, phone|
>     printf "name: %s\naddress: %s\nphone: %s\n\n", 
>       name.inspect, address.inspect, phone.inspect
>   end
> 
>   p db[john]
>   p db[jane]
> end
> 
> 
> ~/eg/ruby > ruby photo.rb 
> 
> name: #<struct Struct::Name first="john", last="doe">
> address: [#<struct Struct::Address addr1="foo", addr2="bar", city="boulder", zip="80304">, #<struct Struct::Phone home="1", work="2", mobile="3">]
> phone: nil
> 
> name: #<struct Struct::Name first="jane", last="doe">
> address: [#<struct Struct::Address addr1="bar", addr2="foo", city="boulder", zip="80305">, #<struct Struct::Phone home="3", work="2", mobile="1">]
> phone: nil
> 
> [#<struct Struct::Address addr1="foo", addr2="bar", city="boulder", zip="80304">, #<struct Struct::Phone home="1", work="2", mobile="3">]
> [#<struct Struct::Address addr1="bar", addr2="foo", city="boulder", zip="80305">, #<struct Struct::Phone home="3", work="2", mobile="1">]
> 
> 
> you can obviously just store the path to the photo this way...  the thing with
> pstore is that you can tailor the object to meet your needs: perhaps a hash
> would be better: it's up to you.  also check out madeleine (on RAA) for this
> purpose.
> 
> 
> -a

Thanks Ara, I'll definitely will try your example above. And check out 
madeline as well.

One question though, have you tried the pstore for multi-user or this is 
mainly for single user only? What happen if 2 or more user accessing the 
same db at the same time? Thanks

/useko