Re: Simple Ruby DB apps/programs ...

On Mon, 5 Jan 2004, Useko Netsumi wrote:

> Date: Mon, 05 Jan 2004 19:25:27 -0500
> From: Useko Netsumi <[e-mail]>
> Reply-To: [e-mail]
> 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
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