# frozen-string-literal: true
module Sequel
class Model
extend Enumerable
extend Inflections
# Class methods for Sequel::Model that implement basic model functionality.
#
# * All of the method names in Model::DATASET_METHODS have class methods created that call
# the Model's dataset with the method of the same name with the given arguments.
module ClassMethods
# Which columns should be the only columns allowed in a call to a mass assignment method (e.g. set)
# (default: not set, so all columns not otherwise restricted are allowed).
attr_reader :allowed_columns
# Whether to cache the anonymous models created by Sequel::Model(). This is
# required for reloading them correctly (avoiding the superclass mismatch). True
# by default for backwards compatibility.
attr_accessor :cache_anonymous_models
# Array of modules that extend this model's dataset. Stored
# so that if the model's dataset is changed, it will be extended
# with all of these modules.
attr_reader :dataset_method_modules
# The default options to use for Model#set_fields. These are merged with
# the options given to set_fields.
attr_accessor :default_set_fields_options
# SQL string fragment used for faster DELETE statement creation when deleting/destroying
# model instances, or nil if the optimization should not be used. For internal use only.
attr_reader :fast_instance_delete_sql
# The dataset that instance datasets (#this) are based on. Generally a naked version of
# the model's dataset limited to one row. For internal use only.
attr_reader :instance_dataset
# Array of plugin modules loaded by this class
#
# Sequel::Model.plugins
# # => [Sequel::Model, Sequel::Model::Associations]
attr_reader :plugins
# The primary key for the class. Sequel can determine this automatically for
# many databases, but not all, so you may need to set it manually. If not
# determined automatically, the default is :id.
attr_reader :primary_key
# Whether to raise an error instead of returning nil on a failure
# to save/create/save_changes/update/destroy due to a validation failure or
# a before_* hook returning false (default: true).
attr_accessor :raise_on_save_failure
# Whether to raise an error when unable to typecast data for a column
# (default: false). This should be set to true if you want to have model
# setter methods raise errors if the argument cannot be typecast properly.
attr_accessor :raise_on_typecast_failure
# Whether to raise an error if an UPDATE or DELETE query related to
# a model instance does not modify exactly 1 row. If set to false,
# Sequel will not check the number of rows modified (default: true).
attr_accessor :require_modification
# Requires that all models have valid tables, raising exceptions if creating a model
# without a valid table backing it. Enabling this will break code like:
#
# class Foo < Sequel::Model
# set_dataset :my_foo
# end
#
# As when Sequel::Model is subclassed, before set_dataset is executed, it will try to
# get the schema for the foos table, which will raise an exception. You would need to
# switch to using:
#
# class Foo < Sequel::Model(:my_foo)
# end
#
# or:
#
# Foo = Sequel::Model()
# Foo.set_dataset :my_foo
attr_accessor :require_valid_table
# Should be the literal primary key column name if this Model's table has a simple primary key, or
# nil if the model has a compound primary key or no primary key.
attr_reader :simple_pk
# Should be the literal table name if this Model's dataset is a simple table (no select, order, join, etc.),
# or nil otherwise. This and simple_pk are used for an optimization in Model.[].
attr_reader :simple_table
# Whether new/set/update and their variants should raise an error
# if an invalid key is used. A key is invalid if no setter method exists
# for that key or the access to the setter method is restricted (e.g. due to it
# being a primary key field). If set to false, silently skip
# any key where the setter method doesn't exist or access to it is restricted.
attr_accessor :strict_param_setting
# Whether to typecast the empty string ('') to nil for columns that
# are not string or blob. In most cases the empty string would be the
# way to specify a NULL SQL value in string form (nil.to_s == ''),
# and an empty string would not usually be typecast correctly for other
# types, so the default is true.
attr_accessor :typecast_empty_string_to_nil
# Whether to typecast attribute values on assignment (default: true).
# If set to false, no typecasting is done, so it will be left up to the
# database to typecast the value correctly.
attr_accessor :typecast_on_assignment
# Whether to enable the after_commit and after_rollback hooks when saving/destroying
# instances. On by default, can be turned off for performance reasons or when using
# prepared transactions (which aren't compatible with after commit/rollback).
attr_accessor :use_after_commit_rollback
# Whether to use a transaction by default when saving/deleting records (default: true).
# If you are sending database queries in before_* or after_* hooks, you shouldn't change
# the default setting without a good reason.
attr_accessor :use_transactions
# Define a Model method on the given module that calls the Model
# method on the receiver. This is how the Sequel::Model() method is
# defined, and allows you to define Model() methods on other modules,
# making it easier to have custom model settings for all models under
# a namespace. Example:
#
# module Foo
# Model = Class.new(Sequel::Model)
# Model.def_Model(self)
# DB = Model.db = Sequel.connect(ENV['FOO_DATABASE_URL'])
# Model.plugin :prepared_statements
#
# class Bar < Model
# # Uses Foo::DB[:bars]
# end
#
# class Baz < Model(:my_baz)
# # Uses Foo::DB[:my_baz]
# end
# end
def def_Model(mod)
model = self
(class << mod; self; end).send(:define_method, :Model) do |source|
model.Model(source)
end
end
# Lets you create a Model subclass with its dataset already set.
# +source+ should be an instance of one of the following classes:
#
# Database :: Sets the database for this model to +source+.
# Generally only useful when subclassing directly
# from the returned class, where the name of the
# subclass sets the table name (which is combined
# with the +Database+ in +source+ to create the
# dataset to use)
# Dataset :: Sets the dataset for this model to +source+.
# other :: Sets the table name for this model to +source+. The
# class will use the default database for model
# classes in order to create the dataset.
#
# The purpose of this method is to set the dataset/database automatically
# for a model class, if the table name doesn't match the implicit
# name. This is neater than using set_dataset inside the class,
# doesn't require a bogus query for the schema.
#
# When creating subclasses of Sequel::Model itself, this method is usually
# called on Sequel itself, using Sequel::Model(:something).
#
# # Using a symbol
# class Comment < Sequel::Model(:something)
# table_name # => :something
# end
#
# # Using a dataset
# class Comment < Sequel::Model(DB1[:something])
# dataset # => DB1[:something]
# end
#
# # Using a database
# class Comment < Sequel::Model(DB1)
# dataset # => DB1[:comments]
# end
def Model(source)
if cache_anonymous_models
mutex = @Model_mutex
cache = mutex.synchronize{@Model_cache ||= {}}
if klass = mutex.synchronize{cache[source]}
return klass
end
end
klass = Class.new(self)
if source.is_a?(::Sequel::Database)
klass.db = source
else
klass.set_dataset(source)
end
if cache_anonymous_models
mutex.synchronize{cache[source] = klass}
end
klass
end
# Returns the first record from the database matching the conditions.
# If a hash is given, it is used as the conditions. If another
# object is given, it finds the first record whose primary key(s) match
# the given argument(s). If no object is returned by the dataset, returns nil.
#
# Artist[1] # SELECT * FROM artists WHERE id = 1
# # => #1, ...}>
#
# Artist[:name=>'Bob'] # SELECT * FROM artists WHERE (name = 'Bob') LIMIT 1
# # => #'Bob', ...}>
def [](*args)
args = args.first if args.size <= 1
args.is_a?(Hash) ? first_where(args) : (primary_key_lookup(args) unless args.nil?)
end
# Initializes a model instance as an existing record. This constructor is
# used by Sequel to initialize model instances when fetching records.
# Requires that values be a hash where all keys are symbols. It
# probably should not be used by external code.
def call(values)
o = allocate
o.instance_variable_set(:@values, values)
o
end
# Clear the setter_methods cache
def clear_setter_methods_cache
@setter_methods = nil
end
# Returns the columns in the result set in their original order.
# Generally, this will use the columns determined via the database
# schema, but in certain cases (e.g. models that are based on a joined
# dataset) it will use Dataset#columns to find the columns.
#
# Artist.columns
# # => [:id, :name]
def columns
@columns || set_columns(dataset.naked.columns)
end
# Creates instance using new with the given values and block, and saves it.
#
# Artist.create(:name=>'Bob')
# # INSERT INTO artists (name) VALUES ('Bob')
#
# Artist.create do |a|
# a.name = 'Jim'
# end # INSERT INTO artists (name) VALUES ('Jim')
def create(values = {}, &block)
new(values, &block).save
end
# Returns the dataset associated with the Model class. Raises
# an +Error+ if there is no associated dataset for this class.
# In most cases, you don't need to call this directly, as Model
# proxies many dataset methods to the underlying dataset.
#
# Artist.dataset.all # SELECT * FROM artists
def dataset
@dataset || raise(Error, "No dataset associated with #{self}")
end
# Alias of set_dataset
def dataset=(ds)
set_dataset(ds)
end
# Extend the dataset with a module, similar to adding
# a plugin with the methods defined in DatasetMethods.
# This is the recommended way to add methods to model datasets.
#
# If an argument, it should be a module, and is used to extend
# the underlying dataset. Otherwise an anonymous module is created, and
# if a block is given, it is module_evaled, allowing you do define
# dataset methods directly using the standard ruby def syntax.
# Returns the module given or the anonymous module created.
#
# # Usage with existing module
# Artist.dataset_module Sequel::ColumnsIntrospection
#
# # Usage with anonymous module
# Artist.dataset_module do
# def foo
# :bar
# end
# end
# Artist.dataset.foo
# # => :bar
# Artist.foo
# # => :bar
#
# Any anonymous modules created are actually instances of Sequel::Model::DatasetModule
# (a Module subclass), which allows you to call the subset method on them:
#
# Artist.dataset_module do
# subset :released, Sequel.identifier(release_date) > Sequel::CURRENT_DATE
# end
#
# Any public methods in the dataset module will have class methods created that
# call the method on the dataset, assuming that the class method is not already
# defined.
def dataset_module(mod = nil)
if mod
raise Error, "can't provide both argument and block to Model.dataset_module" if block_given?
dataset_extend(mod)
mod
else
@dataset_module ||= DatasetModule.new(self)
@dataset_module.module_eval(&Proc.new) if block_given?
dataset_extend(@dataset_module)
@dataset_module
end
end
# Returns the database associated with the Model class.
# If this model doesn't have a database associated with it,
# assumes the superclass's database, or the first object in
# Sequel::DATABASES. If no Sequel::Database object has
# been created, raises an error.
#
# Artist.db.transaction do # BEGIN
# Artist.create(:name=>'Bob')
# # INSERT INTO artists (name) VALUES ('Bob')
# end # COMMIT
def db
return @db if @db
@db = self == Model ? Sequel.synchronize{DATABASES.first} : superclass.db
raise(Error, "No database associated with #{self}: have you called Sequel.connect or #{self}.db= ?") unless @db
@db
end
# Sets the database associated with the Model class. If the
# model has an associated dataset, sets the model's dataset
# to a dataset on the new database with the same options
# used by the current dataset. This can be used directly on
# Sequel::Model to set the default database to be used
# by subclasses, or to override the database used for specific
# models:
#
# Sequel::Model.db = DB1
# Artist.db = DB2
#
# Note that you should not use this to change the model's database
# at runtime. If you have that need, you should look into Sequel's
# sharding support.
def db=(db)
@db = db
set_dataset(db.dataset.clone(@dataset.opts)) if @dataset
end
# Returns the cached schema information if available or gets it
# from the database. This is a hash where keys are column symbols
# and values are hashes of information related to the column. See
# Database#schema.
#
# Artist.db_schema
# # {:id=>{:type=>:integer, :primary_key=>true, ...},
# # :name=>{:type=>:string, :primary_key=>false, ...}}
def db_schema
@db_schema ||= get_db_schema
end
# Create a column alias, where the column methods have one name, but the underlying storage uses a
# different name.
def def_column_alias(meth, column)
clear_setter_methods_cache
overridable_methods_module.module_eval do
define_method(meth){self[column]}
define_method("#{meth}="){|v| self[column] = v}
end
end
# If a block is given, define a method on the dataset (if the model currently has an dataset) with the given argument name using
# the given block. Also define a class method on the model that calls the
# dataset method. Stores the method name and block so that it can be reapplied if the model's
# dataset changes.
#
# If a block is not given, just define a class method on the model for each argument
# that calls the dataset method of the same argument name.
#
# It is recommended that you define methods inside a block passed to #dataset_module
# instead of using this method, as #dataset_module allows you to use normal
# ruby def syntax.
#
# # Add new dataset method and class method that calls it
# Artist.def_dataset_method(:by_name){order(:name)}
# Artist.filter(:name.like('A%')).by_name
# Artist.by_name.filter(:name.like('A%'))
#
# # Just add a class method that calls an existing dataset method
# Artist.def_dataset_method(:server!)
# Artist.server!(:server1)
def def_dataset_method(*args, &block)
raise(Error, "No arguments given") if args.empty?
if block
raise(Error, "Defining a dataset method using a block requires only one argument") if args.length > 1
dataset_module{define_method(args.first, &block)}
else
args.each{|arg| def_model_dataset_method(arg)}
end
end
# Finds a single record according to the supplied filter.
# You are encouraged to use Model.[] or Model.first instead of this method.
#
# Artist.find(:name=>'Bob')
# # SELECT * FROM artists WHERE (name = 'Bob') LIMIT 1
#
# Artist.find{name > 'M'}
# # SELECT * FROM artists WHERE (name > 'M') LIMIT 1
def find(*args, &block)
if args.length == 1 && !block
# Use optimized finder
first_where(args.first)
else
filter(*args, &block).first
end
end
# Like +find+ but invokes create with given conditions when record does not
# exist. Unlike +find+ in that the block used in this method is not passed
# to +find+, but instead is passed to +create+ only if +find+ does not
# return an object.
#
# Artist.find_or_create(:name=>'Bob')
# # SELECT * FROM artists WHERE (name = 'Bob') LIMIT 1
# # INSERT INTO artists (name) VALUES ('Bob')
#
# Artist.find_or_create(:name=>'Jim'){|a| a.hometown = 'Sactown'}
# # SELECT * FROM artists WHERE (name = 'Jim') LIMIT 1
# # INSERT INTO artists (name, hometown) VALUES ('Jim', 'Sactown')
def find_or_create(cond, &block)
find(cond) || create(cond, &block)
end
FINDER_TYPES = [:first, :all, :each, :get].freeze
# Create an optimized finder method using a dataset placeholder literalizer.
# This pre-computes the SQL to use for the query, except for given arguments.
#
# There are two ways to use this. The recommended way is to pass a symbol
# that represents a model class method that returns a dataset:
#
# def Artist.by_name(name)
# where(:name=>name)
# end
#
# Artist.finder :by_name
#
# This creates an optimized first_by_name method, which you can call normally:
#
# Artist.first_by_name("Joe")
#
# The alternative way to use this to pass your own block:
#
# Artist.finder(:name=>:first_by_name){|pl, ds| ds.where(:name=>pl.arg).limit(1)}
#
# Note that if you pass your own block, you are responsible for manually setting
# limits if necessary (as shown above).
#
# Options:
# :arity :: When using a symbol method name, this specifies the arity of the method.
# This should be used if if the method accepts an arbitrary number of arguments,
# or the method has default argument values. Note that if the method is defined
# as a dataset method, the class method Sequel creates accepts an arbitrary number
# of arguments, so you should use this option in that case. If you want to handle
# multiple possible arities, you need to call the finder method multiple times with
# unique :arity and :name methods each time.
# :name :: The name of the method to create. This must be given if you pass a block.
# If you use a symbol, this defaults to the symbol prefixed by the type.
# :mod :: The module in which to create the finder method. Defaults to the singleton
# class of the model.
# :type :: The type of query to run. Can be :first, :each, :all, or :get, defaults to
# :first.
#
# Caveats:
#
# This doesn't handle all possible cases. For example, if you have a method such as:
#
# def Artist.by_name(name)
# name ? where(:name=>name) : exclude(:name=>nil)
# end
#
# Then calling a finder without an argument will not work as you expect.
#
# Artist.finder :by_name
# Artist.by_name(nil).first
# # WHERE (name IS NOT NULL)
# Artist.first_by_name(nil)
# # WHERE (name IS NULL)
#
# See Dataset::PlaceholderLiteralizer for additional caveats.
def finder(meth=OPTS, opts=OPTS, &block)
if block
raise Error, "cannot pass both a method name argument and a block of Model.finder" unless meth.is_a?(Hash)
raise Error, "cannot pass two option hashes to Model.finder" unless opts.equal?(OPTS)
opts = meth
raise Error, "must provide method name via :name option when passing block to Model.finder" unless meth_name = opts[:name]
end
type = opts.fetch(:type, :first)
unless prepare = opts[:prepare]
raise Error, ":type option to Model.finder must be :first, :all, :each, or :get" unless FINDER_TYPES.include?(type)
end
limit1 = type == :first || type == :get
meth_name ||= opts[:name] || :"#{type}_#{meth}"
argn = lambda do |model|
if arity = opts[:arity]
arity
else
method = block || model.method(meth)
(method.arity < 0 ? method.arity.abs - 1 : method.arity)
end
end
loader_proc = if prepare
proc do |model|
args = prepare_method_args('$a', argn.call(model))
ds = if block
model.instance_exec(*args, &block)
else
model.send(meth, *args)
end
ds = ds.limit(1) if limit1
model_name = model.name
if model_name.to_s.empty?
model_name = model.object_id
else
model_name = model_name.gsub(/\W/, '_')
end
ds.prepare(type, :"#{model_name}_#{meth_name}")
end
else
proc do |model|
n = argn.call(model)
block ||= lambda do |pl, model2|
args = (0...n).map{pl.arg}
ds = model2.send(meth, *args)
ds = ds.limit(1) if limit1
ds
end
Sequel::Dataset::PlaceholderLiteralizer.loader(model, &block)
end
end
Sequel.synchronize{@finder_loaders[meth_name] = loader_proc}
mod = opts[:mod] || (class << self; self; end)
if prepare
def_prepare_method(mod, meth_name)
else
def_finder_method(mod, meth_name, type)
end
end
# An alias for calling first on the model's dataset, but with
# optimized handling of the single argument case.
def first(*args, &block)
if args.length == 1 && !block && !args.first.is_a?(Integer)
# Use optimized finder
first_where(args.first)
else
dataset.first(*args, &block)
end
end
# An alias for calling first! on the model's dataset, but with
# optimized handling of the single argument case.
def first!(*args, &block)
first(*args, &block) || raise(Sequel::NoMatchingRow.new(dataset))
end
# Clear the setter_methods cache when a module is included, as it
# may contain setter methods.
def include(*mods)
clear_setter_methods_cache
super
end
# If possible, set the dataset for the model subclass as soon as it
# is created. Also, make sure the inherited class instance variables
# are copied into the subclass.
#
# Sequel queries the database to get schema information as soon as
# a model class is created:
#
# class Artist < Sequel::Model # Causes schema query
# end
def inherited(subclass)
super
ivs = subclass.instance_variables.collect(&:to_s)
inherited_instance_variables.each do |iv, dup|
next if ivs.include?(iv.to_s)
if (sup_class_value = instance_variable_get(iv)) && dup
sup_class_value = case dup
when :dup
sup_class_value.dup
when :hash_dup
h = {}
sup_class_value.each{|k,v| h[k] = v.dup}
h
when Proc
dup.call(sup_class_value)
else
raise Error, "bad inherited instance variable type: #{dup.inspect}"
end
end
subclass.instance_variable_set(iv, sup_class_value)
end
unless ivs.include?("@dataset")
if @dataset && self != Model
subclass.set_dataset(@dataset.clone, :inherited=>true)
elsif (n = subclass.name) && !n.to_s.empty?
db
subclass.set_dataset(subclass.implicit_table_name)
end
end
end
# Returns the implicit table name for the model class, which is the demodulized,
# underscored, pluralized name of the class.
#
# Artist.implicit_table_name # => :artists
# Foo::ArtistAlias.implicit_table_name # => :artist_aliases
def implicit_table_name
pluralize(underscore(demodulize(name))).to_sym
end
# Calls #call with the values hash. Only for backwards compatibility.
def load(values)
call(values)
end
# Clear the setter_methods cache when a setter method is added
def method_added(meth)
clear_setter_methods_cache if meth.to_s =~ SETTER_METHOD_REGEXP
super
end
# Mark the model as not having a primary key. Not having a primary key
# can cause issues, among which is that you won't be able to update records.
#
# Artist.primary_key # => :id
# Artist.no_primary_key
# Artist.primary_key # => nil
def no_primary_key
clear_setter_methods_cache
self.simple_pk = @primary_key = nil
end
# Loads a plugin for use with the model class, passing optional arguments
# to the plugin. If the plugin is a module, load it directly. Otherwise,
# require the plugin from either sequel/plugins/#{plugin} or
# sequel_#{plugin}, and then attempt to load the module using a
# the camelized plugin name under Sequel::Plugins.
def plugin(plugin, *args, &block)
m = plugin.is_a?(Module) ? plugin : plugin_module(plugin)
unless @plugins.include?(m)
@plugins << m
m.apply(self, *args, &block) if m.respond_to?(:apply)
extend(m::ClassMethods) if plugin_module_defined?(m, :ClassMethods)
include(m::InstanceMethods) if plugin_module_defined?(m, :InstanceMethods)
if plugin_module_defined?(m, :DatasetMethods)
dataset_extend(m::DatasetMethods, :create_class_methods=>false)
end
end
m.configure(self, *args, &block) if m.respond_to?(:configure)
end
# Returns primary key attribute hash. If using a composite primary key
# value such be an array with values for each primary key in the correct
# order. For a standard primary key, value should be an object with a
# compatible type for the key. If the model does not have a primary key,
# raises an +Error+.
#
# Artist.primary_key_hash(1) # => {:id=>1}
# Artist.primary_key_hash([1, 2]) # => {:id1=>1, :id2=>2}
def primary_key_hash(value)
case key = @primary_key
when Symbol
{key => value}
when Array
hash = {}
key.zip(Array(value)){|k,v| hash[k] = v}
hash
else
raise(Error, "#{self} does not have a primary key")
end
end
# Return a hash where the keys are qualified column references. Uses the given
# qualifier if provided, or the table_name otherwise. This is useful if you
# plan to join other tables to this table and you want the column references
# to be qualified.
#
# Artist.filter(Artist.qualified_primary_key_hash(1))
# # SELECT * FROM artists WHERE (artists.id = 1)
def qualified_primary_key_hash(value, qualifier=table_name)
case key = @primary_key
when Symbol
{SQL::QualifiedIdentifier.new(qualifier, key) => value}
when Array
hash = {}
key.zip(Array(value)){|k,v| hash[SQL::QualifiedIdentifier.new(qualifier, k)] = v}
hash
else
raise(Error, "#{self} does not have a primary key")
end
end
# Similar to finder, but uses a prepared statement instead of a placeholder
# literalizer. This makes the SQL used static (cannot vary per call), but
# allows binding argument values instead of literalizing them into the SQL
# query string.
#
# If a block is used with this method, it is instance_execed by the model,
# and should accept the desired number of placeholder arguments.
#
# The options are the same as the options for finder, with the following
# exception:
# :type :: Specifies the type of prepared statement to create
def prepared_finder(meth=OPTS, opts=OPTS, &block)
if block
raise Error, "cannot pass both a method name argument and a block of Model.finder" unless meth.is_a?(Hash)
meth = meth.merge(:prepare=>true)
else
opts = opts.merge(:prepare=>true)
end
finder(meth, opts, &block)
end
# Restrict the setting of the primary key(s) when using mass assignment (e.g. +set+). Because
# this is the default, this only make sense to use in a subclass where the
# parent class has used +unrestrict_primary_key+.
def restrict_primary_key
clear_setter_methods_cache
@restrict_primary_key = true
end
# Whether or not setting the primary key(s) when using mass assignment (e.g. +set+) is
# restricted, true by default.
def restrict_primary_key?
@restrict_primary_key
end
# Set the columns to allow when using mass assignment (e.g. +set+). Using this means that
# any columns not listed here will not be modified. If you have any virtual
# setter methods (methods that end in =) that you want to be used during
# mass assignment, they need to be listed here as well (without the =).
#
# It may be better to use a method such as +set_only+ or +set_fields+ that lets you specify
# the allowed fields per call.
#
# Artist.set_allowed_columns(:name, :hometown)
# Artist.set(:name=>'Bob', :hometown=>'Sactown') # No Error
# Artist.set(:name=>'Bob', :records_sold=>30000) # Error
def set_allowed_columns(*cols)
clear_setter_methods_cache
@allowed_columns = cols
end
# Sets the dataset associated with the Model class. +ds+ can be a +Symbol+,
# +LiteralString+, SQL::Identifier, SQL::QualifiedIdentifier,
# SQL::AliasedExpression
# (all specifying a table name in the current database), or a +Dataset+.
# If a dataset is used, the model's database is changed to the database of the given
# dataset. If a dataset is not used, a dataset is created from the current
# database with the table name given. Other arguments raise an +Error+.
# Returns self.
#
# This changes the row_proc of the dataset to return
# model objects and extends the dataset with the dataset_method_modules.
# It also attempts to determine the database schema for the model,
# based on the given dataset.
#
# Artist.set_dataset(:tbl_artists)
# Artist.set_dataset(DB[:artists])
#
# Note that you should not use this to change the model's dataset
# at runtime. If you have that need, you should look into Sequel's
# sharding support.
def set_dataset(ds, opts=OPTS)
inherited = opts[:inherited]
@dataset = convert_input_dataset(ds)
@require_modification = Sequel::Model.require_modification.nil? ? @dataset.provides_accurate_rows_matched? : Sequel::Model.require_modification
if inherited
self.simple_table = superclass.simple_table
@columns = superclass.instance_variable_get(:@columns)
@db_schema = superclass.instance_variable_get(:@db_schema)
else
@dataset_method_modules.each{|m| @dataset.extend(m)} if @dataset_method_modules
@db_schema = get_db_schema
end
@dataset.model = self if @dataset.respond_to?(:model=)
reset_instance_dataset
self
end
# Sets the primary key for this model. You can use either a regular
# or a composite primary key. To not use a primary key, set to nil
# or use +no_primary_key+. On most adapters, Sequel can automatically
# determine the primary key to use, so this method is not needed often.
#
# class Person < Sequel::Model
# # regular key
# set_primary_key :person_id
# end
#
# class Tagging < Sequel::Model
# # composite key
# set_primary_key [:taggable_id, :tag_id]
# end
def set_primary_key(key)
clear_setter_methods_cache
if key.is_a?(Array)
if key.length < 2
key = key.first
else
key = key.dup.freeze
end
end
self.simple_pk = if key && !key.is_a?(Array)
(@dataset || db).literal(key)
end
@primary_key = key
end
# Cache of setter methods to allow by default, in order to speed up new/set/update instance methods.
def setter_methods
@setter_methods ||= get_setter_methods
end
# Sets up a dataset method that returns a filtered dataset.
# Sometimes thought of as a scope, and like most dataset methods,
# they can be chained.
# For example:
#
# Topic.subset(:joes, :username.like('%joe%'))
# Topic.subset(:popular){num_posts > 100}
# Topic.subset(:recent){created_on > Date.today - 7}
#
# Allows you to do:
#
# Topic.joes.recent.popular
#
# to get topics with a username that includes joe that
# have more than 100 posts and were created less than
# 7 days ago.
#
# Both the args given and the block are passed to Dataset#filter.
#
# This method creates dataset methods that do not accept arguments. To create
# dataset methods that accept arguments, you should use define a
# method directly inside a #dataset_module block.
def subset(name, *args, &block)
def_dataset_method(name){filter(*args, &block)}
end
# Returns name of primary table for the dataset. If the table for the dataset
# is aliased, returns the aliased name.
#
# Artist.table_name # => :artists
# Sequel::Model(:foo).table_name # => :foo
# Sequel::Model(:foo___bar).table_name # => :bar
def table_name
dataset.first_source_alias
end
# Allow the setting of the primary key(s) when using the mass assignment methods.
# Using this method can open up security issues, be very careful before using it.
#
# Artist.set(:id=>1) # Error
# Artist.unrestrict_primary_key
# Artist.set(:id=>1) # No Error
def unrestrict_primary_key
clear_setter_methods_cache
@restrict_primary_key = false
end
# Return the model instance with the primary key, or nil if there is no matching record.
def with_pk(pk)
primary_key_lookup(pk)
end
# Return the model instance with the primary key, or raise NoMatchingRow if there is no matching record.
def with_pk!(pk)
with_pk(pk) || raise(NoMatchingRow.new(dataset))
end
# Add model methods that call dataset methods
Plugins.def_dataset_methods(self, DATASET_METHODS)
private
# Yield to the passed block and swallow all errors other than DatabaseConnectionErrors.
def check_non_connection_error
begin
db.transaction(:savepoint=>:only){yield}
rescue Sequel::DatabaseConnectionError
raise
rescue Sequel::Error
raise if require_valid_table
end
end
# Convert the given object to a Dataset that should be used as
# this model's dataset.
def convert_input_dataset(ds)
case ds
when Symbol, SQL::Identifier, SQL::QualifiedIdentifier, SQL::AliasedExpression, LiteralString
self.simple_table = db.literal(ds)
ds = db.from(ds)
when Dataset
self.simple_table = if ds.send(:simple_select_all?)
ds.literal(ds.first_source_table)
end
@db = ds.db
else
raise(Error, "Model.set_dataset takes one of the following classes as an argument: Symbol, LiteralString, SQL::Identifier, SQL::QualifiedIdentifier, SQL::AliasedExpression, Dataset")
end
set_dataset_row_proc(ds)
ds
end
# Add the module to the class's dataset_method_modules. Extend the dataset with the
# module if the model has a dataset. Add dataset methods to the class for all
# public dataset methods.
def dataset_extend(mod, opts=OPTS)
@dataset.extend(mod) if @dataset
reset_instance_dataset
dataset_method_modules << mod
unless opts[:create_class_methods] == false
mod.public_instance_methods.each{|meth| def_model_dataset_method(meth)}
end
end
# Create a column accessor for a column with a method name that is hard to use in ruby code.
def def_bad_column_accessor(column)
overridable_methods_module.module_eval do
define_method(column){self[column]}
define_method("#{column}="){|v| self[column] = v}
end
end
# Create the column accessors. For columns that can be used as method names directly in ruby code,
# use a string to define the method for speed. For other columns names, use a block.
def def_column_accessor(*columns)
clear_setter_methods_cache
columns, bad_columns = columns.partition{|x| NORMAL_METHOD_NAME_REGEXP.match(x.to_s)}
bad_columns.each{|x| def_bad_column_accessor(x)}
im = instance_methods.collect(&:to_s)
columns.each do |column|
meth = "#{column}="
overridable_methods_module.module_eval("def #{column}; self[:#{column}] end", __FILE__, __LINE__) unless im.include?(column.to_s)
overridable_methods_module.module_eval("def #{meth}(v); self[:#{column}] = v end", __FILE__, __LINE__) unless im.include?(meth)
end
end
# Define a model method that calls the dataset method with the same name,
# only used for methods with names that can't be presented directly in
# ruby code.
def def_model_dataset_method(meth)
return if respond_to?(meth, true)
if meth.to_s =~ NORMAL_METHOD_NAME_REGEXP
instance_eval("def #{meth}(*args, &block); dataset.#{meth}(*args, &block) end", __FILE__, __LINE__)
else
(class << self; self; end).send(:define_method, meth){|*args, &block| dataset.send(meth, *args, &block)}
end
end
# Define a finder method in the given module with the given method name that
# load rows using the finder with the given name.
def def_finder_method(mod, meth, type)
mod.send(:define_method, meth){|*args, &block| finder_for(meth).send(type, *args, &block)}
end
# Define a prepared_finder method in the given module that will call the associated prepared
# statement.
def def_prepare_method(mod, meth)
mod.send(:define_method, meth){|*args, &block| finder_for(meth).call(prepare_method_arg_hash(args), &block)}
end
# Find the finder to use for the give method. If a finder has not been loaded
# for the method, load the finder and set correctly in the finders hash, then
# return the finder.
def finder_for(meth)
unless finder = Sequel.synchronize{@finders[meth]}
finder_loader = @finder_loaders.fetch(meth)
finder = finder_loader.call(self)
Sequel.synchronize{@finders[meth] = finder}
end
finder
end
# Get the schema from the database, fall back on checking the columns
# via the database if that will return inaccurate results or if
# it raises an error.
def get_db_schema(reload = reload_db_schema?)
set_columns(nil)
return nil unless @dataset
schema_hash = {}
ds_opts = dataset.opts
get_columns = proc{check_non_connection_error{columns} || []}
schema_array = check_non_connection_error{db.schema(dataset, :reload=>reload)} if db.supports_schema_parsing?
if schema_array
schema_array.each{|k,v| schema_hash[k] = v}
# Set the primary key(s) based on the schema information,
# if the schema information includes primary key information
if schema_array.all?{|k,v| v.has_key?(:primary_key)}
pks = schema_array.collect{|k,v| k if v[:primary_key]}.compact
pks.length > 0 ? set_primary_key(pks) : no_primary_key
end
if (select = ds_opts[:select]) && !(select.length == 1 && select.first.is_a?(SQL::ColumnAll))
# We don't remove the columns from the schema_hash,
# as it's possible they will be used for typecasting
# even if they are not selected.
cols = get_columns.call
cols.each{|c| schema_hash[c] ||= {}}
def_column_accessor(*schema_hash.keys)
else
# Dataset is for a single table with all columns,
# so set the columns based on the order they were
# returned by the schema.
cols = schema_array.collect{|k,v| k}
set_columns(cols)
# Also set the columns for the dataset, so the dataset
# doesn't have to do a query to get them.
dataset.instance_variable_set(:@columns, cols)
end
else
# If the dataset uses multiple tables or custom sql or getting
# the schema raised an error, just get the columns and
# create an empty schema hash for it.
get_columns.call.each{|c| schema_hash[c] = {}}
end
schema_hash
end
# Uncached version of setter_methods, to be overridden by plugins
# that want to modify the methods used.
def get_setter_methods
if allowed_columns
allowed_columns.map{|x| "#{x}="}
else
meths = instance_methods.collect(&:to_s).grep(SETTER_METHOD_REGEXP) - RESTRICTED_SETTER_METHODS
meths -= Array(primary_key).map{|x| "#{x}="} if primary_key && restrict_primary_key?
meths
end
end
# A hash of instance variables to automatically set up in subclasses.
# See Sequel::Model::INHERITED_INSTANCE_VARIABLES. It is safe to modify
# the hash returned by this method, though it may not be safe to modify
# values of the hash.
def inherited_instance_variables
INHERITED_INSTANCE_VARIABLES.dup
end
# For the given opts hash and default name or :class option, add a
# :class_name option unless already present which contains the name
# of the class to use as a string. The purpose is to allow late
# binding to the class later using constantize.
def late_binding_class_option(opts, default)
case opts[:class]
when String, Symbol
# Delete :class to allow late binding
class_name = opts.delete(:class).to_s
if (namespace = opts[:class_namespace]) && !class_name.start_with?('::')
class_name = "::#{namespace}::#{class_name}"
end
opts[:class_name] ||= class_name
when Class
opts[:class_name] ||= opts[:class].name
end
opts[:class_name] ||= '::' + ((name || '').split("::")[0..-2] + [camelize(default)]).join('::')
end
# Module that the class includes that holds methods the class adds for column accessors and
# associations so that the methods can be overridden with +super+.
def overridable_methods_module
include(@overridable_methods_module = Module.new) unless @overridable_methods_module
@overridable_methods_module
end
# Returns the module for the specified plugin. If the module is not
# defined, the corresponding plugin required.
def plugin_module(plugin)
module_name = plugin.to_s.gsub(/(^|_)(.)/){|x| x[-1..-1].upcase}
if !Sequel::Plugins.const_defined?(module_name) ||
(Sequel.const_defined?(module_name) &&
Sequel::Plugins.const_get(module_name) == Sequel.const_get(module_name))
begin
require "sequel/plugins/#{plugin}"
rescue LoadError => e
begin
require "sequel_#{plugin}"
rescue LoadError => e2
e.message << "; #{e2.message}"
raise e
end
end
end
Sequel::Plugins.const_get(module_name)
end
# Check if the plugin module +plugin+ defines the constant named by +submod+.
def plugin_module_defined?(plugin, submod)
if RUBY_VERSION >= '1.9'
plugin.const_defined?(submod, false)
else
# :nocov:
plugin.const_defined?(submod)
# :nocov:
end
end
# An hash of prepared argument values for the given arguments, with keys
# starting at a. Used by the methods created by prepared_finder.
def prepare_method_arg_hash(args)
h = {}
prepare_method_args('a', args.length).zip(args).each{|k, v| h[k] = v}
h
end
# An array of prepared statement argument names, of length n and starting with base.
def prepare_method_args(base, n)
(0...n).map do
s = base.to_sym
base = base.next
s
end
end
# Find the row in the dataset that matches the primary key. Uses
# a static SQL optimization if the table and primary key are simple.
#
# This method should not be called with a nil primary key, in case
# it is overridden by plugins which assume that the passed argument
# is valid.
def primary_key_lookup(pk)
if sql = @fast_pk_lookup_sql
sql = sql.dup
ds = dataset
ds.literal_append(sql, pk)
ds.fetch_rows(sql){|r| return ds.row_proc.call(r)}
nil
elsif dataset.joined_dataset?
first_where(qualified_primary_key_hash(pk))
else
first_where(primary_key_hash(pk))
end
end
# Whether to reload the database schema by default, ignoring any cached value.
def reload_db_schema?
false
end
# Reset the cached fast primary lookup SQL if a simple table and primary key
# are used, or set it to nil if not used.
def reset_fast_pk_lookup_sql
@fast_pk_lookup_sql = if @simple_table && @simple_pk
"SELECT * FROM #@simple_table WHERE #@simple_pk = ".freeze
end
@fast_instance_delete_sql = if @simple_table && @simple_pk
"DELETE FROM #@simple_table WHERE #@simple_pk = ".freeze
end
end
# Reset the instance dataset to a modified copy of the current dataset,
# should be used whenever the model's dataset is modified.
def reset_instance_dataset
@finders.clear if @finders
@instance_dataset = @dataset.limit(1).naked if @dataset
end
# Set the columns for this model and create accessor methods for each column.
def set_columns(new_columns)
@columns = new_columns
def_column_accessor(*new_columns) if new_columns
@columns
end
# Set the dataset's row_proc to the current model.
def set_dataset_row_proc(ds)
ds.row_proc = self
end
# Reset the fast primary key lookup SQL when the simple_pk value changes.
def simple_pk=(pk)
@simple_pk = pk
reset_fast_pk_lookup_sql
end
# Reset the fast primary key lookup SQL when the simple_table value changes.
def simple_table=(t)
@simple_table = t
reset_fast_pk_lookup_sql
end
# Returns a copy of the model's dataset with custom SQL
#
# Artist.fetch("SELECT * FROM artists WHERE name LIKE 'A%'")
# Artist.fetch("SELECT * FROM artists WHERE id = ?", 1)
alias fetch with_sql
end
# Sequel::Model instance methods that implement basic model functionality.
#
# * All of the methods in +HOOKS+ and +AROUND_HOOKS+ create instance methods that are called
# by Sequel when the appropriate action occurs. For example, when destroying
# a model object, Sequel will call +around_destroy+, which will call +before_destroy+, do
# the destroy, and then call +after_destroy+.
# * The following instance_methods all call the class method of the same
# name: columns, db, primary_key, db_schema.
# * All of the methods in +BOOLEAN_SETTINGS+ create attr_writers allowing you
# to set values for the attribute. It also creates instance getters returning
# the value of the setting. If the value has not yet been set, it
# gets the default value from the class by calling the class method of the same name.
module InstanceMethods
HOOKS.each{|h| class_eval("def #{h}; end", __FILE__, __LINE__)}
AROUND_HOOKS.each{|h| class_eval("def #{h}; yield end", __FILE__, __LINE__)}
# Define instance method(s) that calls class method(s) of the
# same name. Replaces the construct:
#
# define_method(meth){self.class.send(meth)}
[:columns, :db, :primary_key, :db_schema].each{|meth| class_eval("def #{meth}; self.class.#{meth} end", __FILE__, __LINE__)}
# Define instance method(s) that calls class method(s) of the
# same name, caching the result in an instance variable. Define
# standard attr_writer method for modifying that instance variable.
BOOLEAN_SETTINGS.each{|meth| class_eval("def #{meth}; !defined?(@#{meth}) ? (frozen? ? self.class.#{meth} : (@#{meth} = self.class.#{meth})) : @#{meth} end", __FILE__, __LINE__)}
attr_writer(*BOOLEAN_SETTINGS)
# The hash of attribute values. Keys are symbols with the names of the
# underlying database columns. The returned hash is a reference to the
# receiver's values hash, and modifying it will also modify the receiver's
# values.
#
# Artist.new(:name=>'Bob').values # => {:name=>'Bob'}
# Artist[1].values # => {:id=>1, :name=>'Jim', ...}
attr_reader :values
alias to_hash values
# Get the value of the column. Takes a single symbol or string argument.
# By default it calls send with the argument to get the value. This can
# be overridden if you have columns that conflict with existing
# method names.
alias get_column_value send
# Set the value of the column. Takes two argument. The first is a
# symbol or string argument for the column name, suffixed with =. The
# second is the value to set for the column. By default it calls send
# with the argument to set the value. This can be overridden if you have
# columns that conflict with existing method names (unlikely for setter
# methods, but possible).
alias set_column_value send
# Creates new instance and passes the given values to set.
# If a block is given, yield the instance to the block.
#
# Arguments:
# values :: should be a hash to pass to set.
#
# Artist.new(:name=>'Bob')
#
# Artist.new do |a|
# a.name = 'Bob'
# end
def initialize(values = {})
@values = {}
@new = true
@modified = true
initialize_set(values)
changed_columns.clear
yield self if block_given?
end
# Returns value of the column's attribute.
#
# Artist[1][:id] #=> 1
def [](column)
@values[column]
end
# Sets the value for the given column. If typecasting is enabled for
# this object, typecast the value based on the column's type.
# If this is a new record or the typecasted value isn't the same
# as the current value for the column, mark the column as changed.
#
# a = Artist.new
# a[:name] = 'Bob'
# a.values #=> {:name=>'Bob'}
def []=(column, value)
# If it is new, it doesn't have a value yet, so we should
# definitely set the new value.
# If the column isn't in @values, we can't assume it is
# NULL in the database, so assume it has changed.
v = typecast_value(column, value)
vals = @values
if new? || !vals.include?(column) || v != (c = vals[column]) || v.class != c.class
change_column_value(column, v)
end
end
# Alias of eql?
def ==(obj)
eql?(obj)
end
# If pk is not nil, true only if the objects have the same class and pk.
# If pk is nil, false.
#
# Artist[1] === Artist[1] # true
# Artist.new === Artist.new # false
# Artist[1].set(:name=>'Bob') == Artist[1] # => true
def ===(obj)
pk.nil? ? false : (obj.class == model) && (obj.pk == pk)
end
# class is defined in Object, but it is also a keyword,
# and since a lot of instance methods call class methods,
# this alias makes it so you can use model instead of
# self.class.
#
# Artist.new.model # => Artist
alias_method :model, :class
# The autoincrementing primary key for this model object. Should be
# overridden if you have a composite primary key with one part of it
# being autoincrementing.
def autoincrementing_primary_key
primary_key
end
# Cancel the current action. Should be called in before hooks to halt
# the processing of the action. If a +msg+ argument is given and
# the model instance is configured to raise exceptions on failure,
# sets the message to use for the raised HookFailed exception.
def cancel_action(msg=nil)
raise_hook_failure(msg)
end
# The columns that have been updated. This isn't completely accurate,
# as it could contain columns whose values have not changed.
#
# a = Artist[1]
# a.changed_columns # => []
# a.name = 'Bob'
# a.changed_columns # => [:name]
def changed_columns
@changed_columns ||= []
end
# Deletes and returns +self+. Does not run destroy hooks.
# Look into using +destroy+ instead.
#
# Artist[1].delete # DELETE FROM artists WHERE (id = 1)
# # => #1, ...}>
def delete
raise Sequel::Error, "can't delete frozen object" if frozen?
_delete
self
end
# Like delete but runs hooks before and after delete.
# If before_destroy returns false, returns false without
# deleting the object from the database. Otherwise, deletes
# the item from the database and returns self. Uses a transaction
# if use_transactions is true or if the :transaction option is given and
# true.
#
# Artist[1].destroy # BEGIN; DELETE FROM artists WHERE (id = 1); COMMIT;
# # => #1, ...}>
def destroy(opts = OPTS)
raise Sequel::Error, "can't destroy frozen object" if frozen?
checked_save_failure(opts){checked_transaction(opts){_destroy(opts)}}
end
# Iterates through all of the current values using each.
#
# Album[1].each{|k, v| puts "#{k} => #{v}"}
# # id => 1
# # name => 'Bob'
def each(&block)
@values.each(&block)
end
# Compares model instances by values.
#
# Artist[1] == Artist[1] # => true
# Artist.new == Artist.new # => true
# Artist[1].set(:name=>'Bob') == Artist[1] # => false
def eql?(obj)
(obj.class == model) && (obj.values == @values)
end
# Returns the validation errors associated with this object.
# See +Errors+.
def errors
@errors ||= errors_class.new
end
# Returns true when current instance exists, false otherwise.
# Generally an object that isn't new will exist unless it has
# been deleted. Uses a database query to check for existence,
# unless the model object is new, in which case this is always
# false.
#
# Artist[1].exists? # SELECT 1 FROM artists WHERE (id = 1)
# # => true
# Artist.new.exists?
# # => false
def exists?
new? ? false : !this.get(SQL::AliasedExpression.new(1, :one)).nil?
end
# Ignore the model's setter method cache when this instances extends a module, as the
# module may contain setter methods.
def extend(mod)
@singleton_setter_added = true
super
end
# Freeze the object in such a way that it is still usable but not modifiable.
# Once an object is frozen, you cannot modify it's values, changed_columns,
# errors, or dataset.
def freeze
values.freeze
changed_columns.freeze
unless errors.frozen?
validate
errors.freeze
end
this.freeze if !new? && model.primary_key
super
end
# Value that should be unique for objects with the same class and pk (if pk is not nil), or
# the same class and values (if pk is nil).
#
# Artist[1].hash == Artist[1].hash # true
# Artist[1].set(:name=>'Bob').hash == Artist[1].hash # true
# Artist.new.hash == Artist.new.hash # true
# Artist.new(:name=>'Bob').hash == Artist.new.hash # false
def hash
case primary_key
when Array
[model, !pk.all? ? @values : pk].hash
when Symbol
[model, pk.nil? ? @values : pk].hash
else
[model, @values].hash
end
end
# Returns value for the :id attribute, even if the primary key is
# not id. To get the primary key value, use +pk+.
#
# Artist[1].id # => 1
def id
@values[:id]
end
# Returns a string representation of the model instance including
# the class name and values.
def inspect
"#<#{model.name} @values=#{inspect_values}>"
end
# Returns the keys in +values+. May not include all column names.
#
# Artist.new.keys # => []
# Artist.new(:name=>'Bob').keys # => [:name]
# Artist[1].keys # => [:id, :name]
def keys
@values.keys
end
# Refresh this record using +for_update+ (by default, or the specified style when given)
# unless this is a new record. Returns self. This can be used to make sure no other
# process is updating the record at the same time.
#
# If style is a string, it will be used directly. You should never pass a string
# to this method that is derived from user input, as that can lead to
# SQL injection.
#
# A symbol may be used for database independent locking behavior, but
# all supported symbols have separate methods (e.g. for_update).
#
#
# a = Artist[1]
# Artist.db.transaction do
# a.lock!
# a.update(:name=>'A')
# end
#
# a = Artist[2]
# Artist.db.transaction do
# a.lock!('FOR NO KEY UPDATE')
# a.update(:name=>'B')
# end
def lock!(style=:update)
_refresh(this.lock_style(style)) unless new?
self
end
# Remove elements of the model object that make marshalling fail. Returns self.
#
# a = Artist[1]
# a.marshallable!
# Marshal.dump(a)
def marshallable!
@this = nil
self
end
# Explicitly mark the object as modified, so +save_changes+/+update+ will
# run callbacks even if no columns have changed.
#
# a = Artist[1]
# a.save_changes # No callbacks run, as no changes
# a.modified!
# a.save_changes # Callbacks run, even though no changes made
#
# If a column is given, specifically marked that column as modified,
# so that +save_changes+/+update+ will include that column in the
# update. This should be used if you plan on mutating the column
# value instead of assigning a new column value:
#
# a.modified!(:name)
# a.name.gsub!(/[aeou]/, 'i')
def modified!(column=nil)
if column && !changed_columns.include?(column)
changed_columns << column
end
@modified = true
end
# Whether this object has been modified since last saved, used by
# save_changes to determine whether changes should be saved. New
# values are always considered modified.
#
# a = Artist[1]
# a.modified? # => false
# a.set(:name=>'Jim')
# a.modified? # => true
#
# If a column is given, specifically check if the given column has
# been modified:
#
# a.modified?(:num_albums) # => false
# a.num_albums = 10
# a.modified?(:num_albums) # => true
def modified?(column=nil)
if column
changed_columns.include?(column)
else
@modified || !changed_columns.empty?
end
end
# Returns true if the current instance represents a new record.
#
# Artist.new.new? # => true
# Artist[1].new? # => false
def new?
defined?(@new) ? @new : (@new = false)
end
# Returns the primary key value identifying the model instance.
# Raises an +Error+ if this model does not have a primary key.
# If the model has a composite primary key, returns an array of values.
#
# Artist[1].pk # => 1
# Artist[[1, 2]].pk # => [1, 2]
def pk
raise(Error, "No primary key is associated with this model") unless key = primary_key
if key.is_a?(Array)
vals = @values
key.map{|k| vals[k]}
else
@values[key]
end
end
# Returns a hash mapping the receivers primary key column(s) to their values.
#
# Artist[1].pk_hash # => {:id=>1}
# Artist[[1, 2]].pk_hash # => {:id1=>1, :id2=>2}
def pk_hash
model.primary_key_hash(pk)
end
# Returns a hash mapping the receivers primary key column(s) to their values.
#
# Artist[1].qualified_pk_hash
# # => {Sequel.qualify(:artists, :id)=>1}
# Artist[[1, 2]].qualified_pk_hash
# # => {Sequel.qualify(:artists, :id1)=>1, Sequel.qualify(:artists, :id2)=>2}
def qualified_pk_hash(qualifier=model.table_name)
model.qualified_primary_key_hash(pk, qualifier)
end
# Reloads attributes from database and returns self. Also clears all
# changed_columns information. Raises an +Error+ if the record no longer
# exists in the database.
#
# a = Artist[1]
# a.name = 'Jim'
# a.refresh
# a.name # => 'Bob'
def refresh
raise Sequel::Error, "can't refresh frozen object" if frozen?
_refresh(this)
self
end
# Alias of refresh, but not aliased directly to make overriding in a plugin easier.
def reload
refresh
end
# Creates or updates the record, after making sure the record
# is valid and before hooks execute successfully. Fails if:
#
# * the record is not valid, or
# * before_save returns false, or
# * the record is new and before_create returns false, or
# * the record is not new and before_update returns false.
#
# If +save+ fails and either raise_on_save_failure or the
# :raise_on_failure option is true, it raises ValidationFailed
# or HookFailed. Otherwise it returns nil.
#
# If it succeeds, it returns self.
#
# You can provide an optional list of columns to update, in which
# case it only updates those columns, or a options hash.
#
# Takes the following options:
#
# :changed :: save all changed columns, instead of all columns or the columns given
# :columns :: array of specific columns that should be saved.
# :raise_on_failure :: set to true or false to override the current
# +raise_on_save_failure+ setting
# :server :: set the server/shard on the object before saving, and use that
# server/shard in any transaction.
# :transaction :: set to true or false to override the current
# +use_transactions+ setting
# :validate :: set to false to skip validation
def save(opts=OPTS)
raise Sequel::Error, "can't save frozen object" if frozen?
set_server(opts[:server]) if opts[:server]
_before_validation
if opts[:validate] != false
unless checked_save_failure(opts){_valid?(true, opts)}
raise(ValidationFailed.new(self)) if raise_on_failure?(opts)
return
end
end
checked_save_failure(opts){checked_transaction(opts){_save(opts)}}
end
# Saves only changed columns if the object has been modified.
# If the object has not been modified, returns nil. If unable to
# save, returns false unless +raise_on_save_failure+ is true.
#
# a = Artist[1]
# a.save_changes # => nil
# a.name = 'Jim'
# a.save_changes # UPDATE artists SET name = 'Bob' WHERE (id = 1)
# # => #1, :name=>'Jim', ...}
def save_changes(opts=OPTS)
save(Hash[opts].merge!(:changed=>true)) || false if modified?
end
# Updates the instance with the supplied values with support for virtual
# attributes, raising an exception if a value is used that doesn't have
# a setter method (or ignoring it if strict_param_setting = false).
# Does not save the record.
#
# artist.set(:name=>'Jim')
# artist.name # => 'Jim'
def set(hash)
set_restricted(hash, :default)
end
# Set all values using the entries in the hash, ignoring any setting of
# allowed_columns in the model.
#
# Artist.set_allowed_columns(:num_albums)
# artist.set_all(:name=>'Jim')
# artist.name # => 'Jim'
def set_all(hash)
set_restricted(hash, :all)
end
# For each of the fields in the given array +fields+, call the setter
# method with the value of that +hash+ entry for the field. Returns self.
#
# You can provide an options hash, with the following options currently respected:
# :missing :: Can be set to :skip to skip missing entries or :raise to raise an
# Error for missing entries. The default behavior is not to check for
# missing entries, in which case the default value is used. To be
# friendly with most web frameworks, the missing check will also check
# for the string version of the argument in the hash if given a symbol.
#
# Examples:
#
# artist.set_fields({:name=>'Jim'}, [:name])
# artist.name # => 'Jim'
#
# artist.set_fields({:hometown=>'LA'}, [:name])
# artist.name # => nil
# artist.hometown # => 'Sac'
#
# artist.name # => 'Jim'
# artist.set_fields({}, [:name], :missing=>:skip)
# artist.name # => 'Jim'
#
# artist.name # => 'Jim'
# artist.set_fields({}, [:name], :missing=>:raise)
# # Sequel::Error raised
def set_fields(hash, fields, opts=nil)
opts = if opts
Hash[model.default_set_fields_options].merge!(opts)
else
model.default_set_fields_options
end
case opts[:missing]
when :skip
fields.each do |f|
if hash.has_key?(f)
set_column_value("#{f}=", hash[f])
elsif f.is_a?(Symbol) && hash.has_key?(sf = f.to_s)
set_column_value("#{sf}=", hash[sf])
end
end
when :raise
fields.each do |f|
if hash.has_key?(f)
set_column_value("#{f}=", hash[f])
elsif f.is_a?(Symbol) && hash.has_key?(sf = f.to_s)
set_column_value("#{sf}=", hash[sf])
else
raise(Sequel::Error, "missing field in hash: #{f.inspect} not in #{hash.inspect}")
end
end
else
fields.each{|f| set_column_value("#{f}=", hash[f])}
end
self
end
# Set the values using the entries in the hash, only if the key
# is included in only. It may be a better idea to use +set_fields+
# instead of this method.
#
# artist.set_only({:name=>'Jim'}, :name)
# artist.name # => 'Jim'
#
# artist.set_only({:hometown=>'LA'}, :name) # Raise Error
def set_only(hash, *only)
set_restricted(hash, only.flatten)
end
# Set the shard that this object is tied to. Returns self.
def set_server(s)
@server = s
@this.opts[:server] = s if @this
self
end
# Clear the setter_methods cache when a method is added
def singleton_method_added(meth)
@singleton_setter_added = true if meth.to_s =~ SETTER_METHOD_REGEXP
super
end
# Returns (naked) dataset that should return only this instance.
#
# Artist[1].this
# # SELECT * FROM artists WHERE (id = 1) LIMIT 1
def this
return @this if @this
raise Error, "No dataset for model #{model}" unless ds = model.instance_dataset
cond = if ds.joined_dataset?
qualified_pk_hash
else
pk_hash
end
@this = use_server(ds.where(cond))
end
# Runs #set with the passed hash and then runs save_changes.
#
# artist.update(:name=>'Jim') # UPDATE artists SET name = 'Jim' WHERE (id = 1)
def update(hash)
update_restricted(hash, :default)
end
# Update all values using the entries in the hash, ignoring any setting of
# +allowed_columns+ in the model.
#
# Artist.set_allowed_columns(:num_albums)
# artist.update_all(:name=>'Jim') # UPDATE artists SET name = 'Jim' WHERE (id = 1)
def update_all(hash)
update_restricted(hash, :all)
end
# Update the instances values by calling +set_fields+ with the arguments, then
# saves any changes to the record. Returns self.
#
# artist.update_fields({:name=>'Jim'}, [:name])
# # UPDATE artists SET name = 'Jim' WHERE (id = 1)
#
# artist.update_fields({:hometown=>'LA'}, [:name])
# # UPDATE artists SET name = NULL WHERE (id = 1)
def update_fields(hash, fields, opts=nil)
set_fields(hash, fields, opts)
save_changes
end
# Update the values using the entries in the hash, only if the key
# is included in only. It may be a better idea to use +update_fields+
# instead of this method.
#
# artist.update_only({:name=>'Jim'}, :name)
# # UPDATE artists SET name = 'Jim' WHERE (id = 1)
#
# artist.update_only({:hometown=>'LA'}, :name) # Raise Error
def update_only(hash, *only)
update_restricted(hash, only.flatten)
end
# Validates the object. If the object is invalid, errors should be added
# to the errors attribute. By default, does nothing, as all models
# are valid by default. See the {"Model Validations" guide}[rdoc-ref:doc/validations.rdoc].
# for details about validation. Should not be called directly by
# user code, call valid? instead to check if an object
# is valid.
def validate
end
# Validates the object and returns true if no errors are reported.
#
# artist(:name=>'Valid').valid? # => true
# artist(:name=>'Invalid').valid? # => false
# artist.errors.full_messages # => ['name cannot be Invalid']
def valid?(opts = OPTS)
_before_validation
_valid?(false, opts)
end
private
# Run code directly after the INSERT query, before after_create.
# This is only a temporary API, it should not be overridden by external code.
def _after_create(pk)
@this = nil
@new = false
@was_new = true
end
# Run code after around_save returns, before calling after_commit.
# This is only a temporary API, it should not be overridden by external code.
def _after_save(pk)
if @was_new
@was_new = nil
pk ? _save_refresh : changed_columns.clear
else
@columns_updated = nil
end
@modified = false
end
# Run code directly after the UPDATE query, before after_update.
# This is only a temporary API, it should not be overridden by external code.
def _after_update
@this = nil
end
# Run code before any validation is done, but also run it before saving
# even if validation is skipped. This is a private hook. It exists so that
# plugins can set values automatically before validation (as the values
# need to be validated), but should be set even if validation is skipped.
# Unlike the regular before_validation hook, we do not skip the save/validation
# if this returns false.
def _before_validation
end
# Do the deletion of the object's dataset, and check that the row
# was actually deleted.
def _delete
n = _delete_without_checking
raise(NoExistingObject, "Attempt to delete object did not result in a single row modification (Rows Deleted: #{n}, SQL: #{_delete_dataset.delete_sql})") if require_modification && n != 1
n
end
# The dataset to use when deleting the object. The same as the object's
# dataset by default.
def _delete_dataset
this
end
# Actually do the deletion of the object's dataset. Return the
# number of rows modified.
def _delete_without_checking
if sql = (m = model).fast_instance_delete_sql
sql = sql.dup
ds = use_server(m.dataset)
ds.literal_append(sql, pk)
ds.with_sql_delete(sql)
else
_delete_dataset.delete
end
end
# Internal destroy method, separted from destroy to
# allow running inside a transaction
def _destroy(opts)
sh = {:server=>this_server}
db.after_rollback(sh){after_destroy_rollback} if uacr = use_after_commit_rollback
called = false
around_destroy do
called = true
raise_hook_failure(:before_destroy) if before_destroy == false
_destroy_delete
after_destroy
true
end
raise_hook_failure(:around_destroy) unless called
db.after_commit(sh){after_destroy_commit} if uacr
self
end
# Internal delete method to call when destroying an object,
# separated from delete to allow you to override destroy's version
# without affecting delete.
def _destroy_delete
delete
end
# Insert the record into the database, returning the primary key if
# the record should be refreshed from the database.
def _insert
ds = _insert_dataset
if _use_insert_select?(ds) && (h = _insert_select_raw(ds))
_save_set_values(h)
nil
else
iid = _insert_raw(ds)
# if we have a regular primary key and it's not set in @values,
# we assume it's the last inserted id
if (pk = autoincrementing_primary_key) && pk.is_a?(Symbol) && !(vals = @values)[pk]
vals[pk] = iid
end
pk
end
end
# The dataset to use when inserting a new object. The same as the model's
# dataset by default.
def _insert_dataset
use_server(model.instance_dataset)
end
# Insert into the given dataset and return the primary key created (if any).
def _insert_raw(ds)
ds.insert(_insert_values)
end
# Insert into the given dataset and return the hash of column values.
def _insert_select_raw(ds)
ds.insert_select(_insert_values)
end
# The values hash to use when inserting a new record.
alias _insert_values values
# Refresh using a particular dataset, used inside save to make sure the same server
# is used for reading newly inserted values from the database
def _refresh(dataset)
_refresh_set_values(_refresh_get(dataset) || raise(NoExistingObject, "Record not found"))
changed_columns.clear
end
# Get the row of column data from the database.
def _refresh_get(dataset)
dataset.first
end
# Set the refreshed values after
def _refresh_set_values(h)
@values = h
end
# Internal version of save, split from save to allow running inside
# it's own transaction.
def _save(opts)
sh = {:server=>this_server}
db.after_rollback(sh){after_rollback} if uacr = use_after_commit_rollback
pk = nil
called_save = false
called_cu = false
around_save do
called_save = true
raise_hook_failure(:before_save) if before_save == false
if new?
around_create do
called_cu = true
raise_hook_failure(:before_create) if before_create == false
pk = _insert
_after_create(pk)
after_create
true
end
raise_hook_failure(:around_create) unless called_cu
else
around_update do
called_cu = true
raise_hook_failure(:before_update) if before_update == false
columns = opts[:columns]
if columns.nil?
@columns_updated = if opts[:changed]
@values.reject{|k,v| !changed_columns.include?(k)}
else
_save_update_all_columns_hash
end
changed_columns.clear
else # update only the specified columns
columns = Array(columns)
@columns_updated = @values.reject{|k, v| !columns.include?(k)}
changed_columns.reject!{|c| columns.include?(c)}
end
_update_columns(@columns_updated)
_after_update
after_update
true
end
raise_hook_failure(:around_update) unless called_cu
end
after_save
true
end
raise_hook_failure(:around_save) unless called_save
_after_save(pk)
db.after_commit(sh){after_commit} if uacr
self
end
# Refresh the object after saving it, used to get
# default values of all columns. Separated from _save so it
# can be overridden to avoid the refresh.
def _save_refresh
_save_set_values(_refresh_get(this.server?(:default)) || raise(NoExistingObject, "Record not found"))
changed_columns.clear
end
# Set values to the provided hash. Called after a create,
# to set the full values from the database in the model instance.
def _save_set_values(h)
@values = h
end
# Return a hash of values used when saving all columns of an
# existing object (i.e. not passing specific columns to save
# or using update/save_changes). Defaults to all of the
# object's values except unmodified primary key columns, as some
# databases don't like you setting primary key values even
# to their existing values.
def _save_update_all_columns_hash
v = Hash[@values]
Array(primary_key).each{|x| v.delete(x) unless changed_columns.include?(x)}
v
end
# Call _update with the given columns, if any are present.
# Plugins can override this method in order to update with
# additional columns, even when the column hash is initially empty.
def _update_columns(columns)
_update(columns) unless columns.empty?
end
# Update this instance's dataset with the supplied column hash,
# checking that only a single row was modified.
def _update(columns)
n = _update_without_checking(columns)
raise(NoExistingObject, "Attempt to update object did not result in a single row modification (SQL: #{_update_dataset.update_sql(columns)})") if require_modification && n != 1
n
end
# The dataset to use when updating an object. The same as the object's
# dataset by default.
def _update_dataset
this
end
# Update this instances dataset with the supplied column hash.
def _update_without_checking(columns)
_update_dataset.update(columns)
end
# Whether to use insert_select when inserting a new row.
def _use_insert_select?(ds)
(!ds.opts[:select] || ds.opts[:returning]) && ds.supports_insert_select?
end
# Internal validation method. If +raise_errors+ is +true+, hook
# failures will be raised as HookFailure exceptions. If it is
# +false+, +false+ will be returned instead.
def _valid?(raise_errors, opts)
return errors.empty? if frozen?
errors.clear
called = false
error = false
around_validation do
called = true
if before_validation == false
if raise_errors
raise_hook_failure(:before_validation)
else
error = true
end
false
else
validate
after_validation
errors.empty?
end
end
error = true unless called
if error
if raise_errors
raise_hook_failure(:around_validation)
else
false
end
else
errors.empty?
end
end
# If not raising on failure, check for HookFailed
# being raised by yielding and swallow it.
def checked_save_failure(opts)
if raise_on_failure?(opts)
yield
else
begin
yield
rescue HookFailed
nil
end
end
end
# If transactions should be used, wrap the yield in a transaction block.
def checked_transaction(opts=OPTS)
use_transaction?(opts) ? db.transaction({:server=>this_server}.merge!(opts)){yield} : yield
end
# Change the value of the column to given value, recording the change.
def change_column_value(column, value)
cc = changed_columns
cc << column unless cc.include?(column)
@values[column] = value
end
# Default error class used for errors.
def errors_class
Errors
end
if RUBY_VERSION >= '1.9'
# Clone constructor -- freeze internal data structures if the original's
# are frozen.
def initialize_clone(other)
super
freeze if other.frozen?
self
end
else
# :nocov:
# Ruby 1.8 doesn't support initialize_clone, so override clone to dup and freeze.
def clone
o = dup
o.freeze if frozen?
o
end
public :clone
# :nocov:
end
# Copy constructor -- Duplicate internal data structures.
def initialize_copy(other)
super
@values = Hash[@values]
@changed_columns = @changed_columns.dup if @changed_columns
@errors = @errors.dup if @errors
@this = @this.dup if @this
self
end
# Set the columns with the given hash. By default, the same as +set+, but
# exists so it can be overridden. This is called only for new records, before
# changed_columns is cleared.
def initialize_set(h)
set(h) unless h.empty?
end
# Default inspection output for the values hash, overwrite to change what #inspect displays.
def inspect_values
@values.inspect
end
# Whether to raise or return false if this action fails. If the
# :raise_on_failure option is present in the hash, use that, otherwise,
# fallback to the object's raise_on_save_failure (if set), or
# class's default (if not).
def raise_on_failure?(opts)
opts.fetch(:raise_on_failure, raise_on_save_failure)
end
# Raise an error appropriate to the hook type. May be swallowed by
# checked_save_failure depending on the raise_on_failure? setting.
def raise_hook_failure(type=nil)
msg = case type
when String
type
when Symbol
"the #{type} hook failed"
else
"a hook failed"
end
raise HookFailed.new(msg, self)
end
# Get the ruby class or classes related to the given column's type.
def schema_type_class(column)
if (sch = db_schema[column]) && (type = sch[:type])
db.schema_type_class(type)
end
end
# Call setter methods based on keys in hash, with the appropriate values.
# Restrict which methods can be called based on the provided type.
def set_restricted(hash, type)
return self if hash.empty?
meths = setter_methods(type)
strict = strict_param_setting
hash.each do |k,v|
m = "#{k}="
if meths.include?(m)
set_column_value(m, v)
elsif strict
# Avoid using respond_to? or creating symbols from user input
if public_methods.map(&:to_s).include?(m)
if Array(model.primary_key).map(&:to_s).member?(k.to_s) && model.restrict_primary_key?
raise MassAssignmentRestriction, "#{k} is a restricted primary key"
else
raise MassAssignmentRestriction, "#{k} is a restricted column"
end
else
raise MassAssignmentRestriction, "method #{m} doesn't exist"
end
end
end
self
end
# Returns all methods that can be used for attribute assignment (those that end with =),
# depending on the type:
#
# :default :: Use the default methods allowed in the model class.
# :all :: Allow setting all setters, except those specifically restricted (such as ==).
# Array :: Only allow setting of columns in the given array.
def setter_methods(type)
if type == :default
if !@singleton_setter_added || model.allowed_columns
return model.setter_methods
end
end
if type.is_a?(Array)
type.map{|x| "#{x}="}
else
meths = methods.collect(&:to_s).grep(SETTER_METHOD_REGEXP) - RESTRICTED_SETTER_METHODS
meths -= Array(primary_key).map{|x| "#{x}="} if type != :all && primary_key && model.restrict_primary_key?
meths
end
end
# The server/shard that the model object's dataset uses, or :default if the
# model object's dataset does not have an associated shard.
def this_server
if (s = @server)
s
elsif (t = @this)
t.opts[:server] || :default
else
model.dataset.opts[:server] || :default
end
end
# Typecast the value to the column's type if typecasting. Calls the database's
# typecast_value method, so database adapters can override/augment the handling
# for database specific column types.
def typecast_value(column, value)
return value unless typecast_on_assignment && db_schema && (col_schema = db_schema[column])
value = nil if '' == value and typecast_empty_string_to_nil and col_schema[:type] and ![:string, :blob].include?(col_schema[:type])
raise(InvalidValue, "nil/NULL is not allowed for the #{column} column") if raise_on_typecast_failure && value.nil? && (col_schema[:allow_null] == false)
begin
model.db.typecast_value(col_schema[:type], value)
rescue InvalidValue
raise_on_typecast_failure ? raise : value
end
end
# Set the columns, filtered by the only and except arrays.
def update_restricted(hash, type)
set_restricted(hash, type)
save_changes
end
# Set the given dataset to use the current object's shard.
def use_server(ds)
@server ? ds.server(@server) : ds
end
# Whether to use a transaction for this action. If the :transaction
# option is present in the hash, use that, otherwise, fallback to the
# object's default (if set), or class's default (if not).
def use_transaction?(opts = OPTS)
opts.fetch(:transaction, use_transactions)
end
end
# Dataset methods are methods that the model class extends its dataset with in
# the call to set_dataset.
module DatasetMethods
# The model class associated with this dataset
#
# Artist.dataset.model # => Artist
attr_accessor :model
# Assume if a single integer is given that it is a lookup by primary
# key, and call with_pk with the argument.
#
# Artist.dataset[1] # SELECT * FROM artists WHERE (id = 1) LIMIT 1
def [](*args)
if args.length == 1 && (i = args.at(0)) && i.is_a?(Integer)
with_pk(i)
else
super
end
end
# Destroy each row in the dataset by instantiating it and then calling
# destroy on the resulting model object. This isn't as fast as deleting
# the dataset, which does a single SQL call, but this runs any destroy
# hooks on each object in the dataset.
#
# Artist.dataset.destroy
# # DELETE FROM artists WHERE (id = 1)
# # DELETE FROM artists WHERE (id = 2)
# # ...
def destroy
pr = proc{all(&:destroy).length}
model.use_transactions ? @db.transaction(:server=>opts[:server], &pr) : pr.call
end
# Allow Sequel::Model classes to be used as dataset arguments when graphing:
#
# Artist.graph(Album, :artist_id=>id)
# # SELECT artists.id, artists.name, albums.id AS albums_id, albums.artist_id, albums.name AS albums_name
# # FROM artists LEFT OUTER JOIN albums ON (albums.artist_id = artists.id)
def graph(table, *args, &block)
if table.is_a?(Class) && table < Sequel::Model
super(table.dataset, *args, &block)
else
super
end
end
# Handle Sequel::Model instances when inserting, using the model instance's
# values for the insert, unless the model instance can be used directly in
# SQL.
#
# Album.insert(Album.load(:name=>'A'))
# # INSERT INTO albums (name) VALUES ('A')
def insert_sql(*values)
if values.size == 1 && (v = values.at(0)).is_a?(Sequel::Model) && !v.respond_to?(:sql_literal_append)
super(v.to_hash)
else
super
end
end
# Allow Sequel::Model classes to be used as table name arguments in dataset
# join methods:
#
# Artist.join(Album, :artist_id=>id)
# # SELECT * FROM artists INNER JOIN albums ON (albums.artist_id = artists.id)
def join_table(type, table, *args, &block)
if table.is_a?(Class) && table < Sequel::Model
if table.dataset.simple_select_all?
super(type, table.table_name, *args, &block)
else
super(type, table.dataset, *args, &block)
end
else
super
end
end
# If there is no order already defined on this dataset, order it by
# the primary key and call last.
#
# Album.last
# # SELECT * FROM albums ORDER BY id DESC LIMIT 1
def last(*a, &block)
if opts[:order].nil? && model && (pk = model.primary_key)
order(*pk).last(*a, &block)
else
super
end
end
# If there is no order already defined on this dataset, order it by
# the primary key and call paged_each.
#
# Album.paged_each{|row| }
# # SELECT * FROM albums ORDER BY id LIMIT 1000 OFFSET 0
# # SELECT * FROM albums ORDER BY id LIMIT 1000 OFFSET 1000
# # SELECT * FROM albums ORDER BY id LIMIT 1000 OFFSET 2000
# # ...
def paged_each(*a, &block)
if opts[:order].nil? && model && (pk = model.primary_key)
order(*pk).paged_each(*a, &block)
else
super
end
end
# This allows you to call +to_hash+ without any arguments, which will
# result in a hash with the primary key value being the key and the
# model object being the value.
#
# Artist.dataset.to_hash # SELECT * FROM artists
# # => {1=>#1, ...}>,
# # 2=>#2, ...}>,
# # ...}
def to_hash(key_column=nil, value_column=nil, opts=OPTS)
if key_column
super
else
raise(Sequel::Error, "No primary key for model") unless model && (pk = model.primary_key)
super(pk, value_column, opts)
end
end
# Given a primary key value, return the first record in the dataset with that primary key
# value. If no records matches, returns nil.
#
# # Single primary key
# Artist.dataset.with_pk(1)
# # SELECT * FROM artists WHERE (artists.id = 1) LIMIT 1
#
# # Composite primary key
# Artist.dataset.with_pk([1, 2])
# # SELECT * FROM artists WHERE ((artists.id1 = 1) AND (artists.id2 = 2)) LIMIT 1
def with_pk(pk)
first(model.qualified_primary_key_hash(pk))
end
# Same as with_pk, but raises NoMatchingRow instead of returning nil if no
# row matches.
def with_pk!(pk)
with_pk(pk) || raise(NoMatchingRow.new(self))
end
end
extend ClassMethods
plugin self
finder(:where, :arity=>1, :mod=>ClassMethods)
end
end