--- datamapper version 1 Fri Feb 08 02:27:41 +0000 2008
+++ datamapper version 12 Wed Nov 26 20:00:10 +0000 2008
@@ -1,2 +1,116 @@
-has_many :class => "ClassName"
+DataMapper, the ruby object relational mapper
+ website: http://www.datamapper.org
+ git: git://github.com/sam/dm-core.git
+ mail: http://groups.google.com/group/datamapper
+ now: http://www.twitter.com/datamapper
+ help: http://datamapper.lighthouseapp.com/projects/20609-datamapper/
+
+Setting up a Connection
+ DataMapper.setup(:default, "adapter://user:password@hostname/dbname")
+ supported adapters: mysql, sqlite3, postgres, sqlite3::memory:
+ additional adapters are in dm-more, (couchdb, rest, imap, file, saleforce...)
+
+Creating a Model (with properties)
+ class Zoo
+ include DataMapper::Resource
+ property :id, Serial
+ end
+
+
+Properties
+ property :id, Serial # auto-incrementing PK
+ property :name, String, :key => true # natural key
+ # you must specify >= 1 key, CPK support 100%
+
+ # available data-types
+ property :description, Text # (lazy by default)
+ property :created_at, DateTime
+ property :open, Boolean
+ property :admission, BigDecimal
+
+ # require dm-types for Csv, Enum, EpochTime, FilePath, Flag,
+ # IPAddress, URI, Yaml
+
+Property Options (pass as hash)
+ :default, :nullable, :field (column name), :size, :length, :format,
+ :index, :unique_index, :ordinal, :auto_validate, :precision,
+ :scale, :accessor, :reader, :writer, :lazy
+
+
+Finders
+ Zoo.get(PK_HERE)
+ Zoo.first({see_below})
+ Zoo.all({see_below})
+
+Finder Options (pass as hash)
+ :conditions => ["property = ? and property = ?", 'value', 'value']
+ :conditions => {:property => 'value', ...}
+ :property => 'ZooNameHere'
+ # any non-standard key => value pair is assumed a condition if not
+ # otherwise recognized
+ :property.lte => 12.00 # <=
+ .gte # >=
+ .gt # >
+ .lt # <
+ .not # NOT =
+ .like # LIKE
+ .in # IN ()
+ 'class.property' => 'value'
+ Class.relationship.property => 'value' # will automatically issue JOINS
+
+Finder Gotcha
+ :order => [:created_at.desc, ...] # descending sort
+ .asc # ascending
+
+
+Associations
+ has 1 # has_one
+ has n # has_many
+ belongs_to :things
+ has n, :things, :through => :more_things
+ has n, :things, :through => Resource # has_and_belongs_to_many
+
+Association Options
+ (any Finder Options)
+ :class_name => 'ClassNameHere'
+ :order => [:property.desc]
+ :child_key => [:property, ...]
+ :through => :other_association
+
+
+Validations (require 'dm-validations')
+ validates_present :title
+ validates_is_number :rating
+ validates_format :email, :as => :email_address
+ validates_length :summary, :in => (1..100)
+ validates_is_unique :slug
+ validates_with_method (do...end, :method_name)
+
+
+Callbacks AKA "Hooks"
+ Object-level
+ before :method_name, (do...end, :another_method_name)
+ after :method_name, (do...end, :another_method_name)
+ Class-level
+ before_class_method :method_name, (do...end, :another_method_name)
+ after_class_method :method_name, (do...end, :another_method_name)
+
+Callbacks Gotcha
+ Hooks act on 'self' and aren't passed an arguement
+ 'self' for object-level hooks are the instance
+ 'self' for class-level hooks are the class itself
+
+Misc. Stuff & Gotchas
+ Single Table Inheritance
+ property :type, Discriminator # then inherit from this model
+
+ Paranoia
+ property :deleted_at, ParanoidDateTime
+ property :deleted, ParanoidBoolean
+
+ Multiple DB Connections
+ DataMapper.setup(:external, "adapter://username:password@hostname/dbname")
+ repository(:external) do...end
+ Association: has n, :things, :repository => repository(:external)
+ Finder: Thing.all(:repository => repository(:external))
