module Sequel::Model::ClassMethods

Class methods for Sequel::Model that implement basic model functionality.

Constants

FINDER_TYPES

Attributes

allowed_columns[R]

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).

dataset_method_modules[R]

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.

default_set_fields_options[RW]

The default options to use for Model#set_fields. These are merged with the options given to set_fields.

fast_instance_delete_sql[R]

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.

instance_dataset[R]

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.

plugins[R]

Array of plugin modules loaded by this class

Sequel::Model.plugins
# => [Sequel::Model, Sequel::Model::Associations]
primary_key[R]

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.

raise_on_save_failure[RW]

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).

raise_on_typecast_failure[RW]

Whether to raise an error when unable to typecast data for a column (default: true). This should be set to false if you want to use validations to display nice error messages to the user (e.g. most web applications). You can use the validates_schema_types validation (from the validation_helpers plugin) in connection with this setting to check for typecast failures during validation.

require_modification[RW]

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).

simple_pk[R]

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.

simple_table[R]

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.[].

strict_param_setting[RW]

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.

typecast_empty_string_to_nil[RW]

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.

typecast_on_assignment[RW]

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.

use_after_commit_rollback[RW]

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).

use_transactions[RW]

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.

Public Instance Methods

[](*args) click to toggle source

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
# => #<Artist {:id=>1, ...}>

Artist[:name=>'Bob'] # SELECT * FROM artists WHERE (name = 'Bob') LIMIT 1
# => #<Artist {:name=>'Bob', ...}>
# File lib/sequel/model/base.rb, line 108
def [](*args)
  args = args.first if args.size <= 1
  args.is_a?(Hash) ? first_where(args) : (primary_key_lookup(args) unless args.nil?)
end
call(values) click to toggle source

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.

# File lib/sequel/model/base.rb, line 117
def call(values)
  o = allocate
  o.instance_variable_set(:@values, values)
  o
end
clear_setter_methods_cache() click to toggle source

Clear the #setter_methods cache

# File lib/sequel/model/base.rb, line 124
def clear_setter_methods_cache
  @setter_methods = nil
end
columns() click to toggle source

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]
# File lib/sequel/model/base.rb, line 135
def columns
  @columns || set_columns(dataset.naked.columns)
end
create(values = {}, &block) click to toggle source

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')
# File lib/sequel/model/base.rb, line 147
def create(values = {}, &block)
  new(values, &block).save
end
dataset() click to toggle source

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
# File lib/sequel/model/base.rb, line 157
def dataset
  @dataset || raise(Error, "No dataset associated with #{self}")
end
dataset=(ds) click to toggle source

Alias of #set_dataset

# File lib/sequel/model/base.rb, line 162
def dataset=(ds)
  set_dataset(ds)
end
dataset_module(mod = nil) click to toggle source

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.

# File lib/sequel/model/base.rb, line 200
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
db() click to toggle source

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
# File lib/sequel/model/base.rb, line 223
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
db=(db) click to toggle source

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.

# File lib/sequel/model/base.rb, line 244
def db=(db)
  @db = db
  set_dataset(db.dataset.clone(@dataset.opts)) if @dataset
end
db_schema() click to toggle source

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, ...}}
# File lib/sequel/model/base.rb, line 257
def db_schema
  @db_schema ||= get_db_schema
end
def_column_alias(meth, column) click to toggle source

Create a column alias, where the column methods have one name, but the underlying storage uses a different name.

# File lib/sequel/model/base.rb, line 263
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
def_dataset_method(*args, &block) click to toggle source

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)
# File lib/sequel/model/base.rb, line 291
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
find(*args, &block) click to toggle source

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
# File lib/sequel/model/base.rb, line 310
def find(*args, &block)
  if args.length == 1 && !block
    # Use optimized finder
    first_where(args.first)
  else
    filter(*args, &block).first
  end
end
find_or_create(cond, &block) click to toggle source

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')
# File lib/sequel/model/base.rb, line 331
def find_or_create(cond, &block)
  find(cond) || create(cond, &block)
end
finder(meth=OPTS, opts=OPTS, &block) click to toggle source

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.

# File lib/sequel/model/base.rb, line 393
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
first(*args, &block) click to toggle source

An alias for calling first on the model's dataset, but with optimized handling of the single argument case.

# File lib/sequel/model/base.rb, line 459
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
first!(*args, &block) click to toggle source

An alias for calling first! on the model's dataset, but with optimized handling of the single argument case.

# File lib/sequel/model/base.rb, line 470
def first!(*args, &block)
  first(*args, &block) || raise(Sequel::NoMatchingRow)
end
implicit_table_name() click to toggle source

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
# File lib/sequel/model/base.rb, line 529
def implicit_table_name
  pluralize(underscore(demodulize(name))).to_sym
end
include(*mods) click to toggle source

Clear the #setter_methods cache when a module is included, as it may contain setter methods.

Calls superclass method
# File lib/sequel/model/base.rb, line 476
def include(*mods)
  clear_setter_methods_cache
  super
end
inherited(subclass) click to toggle source

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
Calls superclass method
# File lib/sequel/model/base.rb, line 490
def inherited(subclass)
  super
  ivs = subclass.instance_variables.collect{|x| x.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 self == Model || !@dataset
      n = subclass.name
      unless n.nil? || n.empty?
        db
        subclass.set_dataset(subclass.implicit_table_name) rescue nil
      end
    elsif @dataset
      subclass.set_dataset(@dataset.clone, :inherited=>true) rescue nil
    end
  end
end
load(values) click to toggle source

Calls call with the values hash. Only for backwards compatibility.

# File lib/sequel/model/base.rb, line 534
def load(values)
  call(values)
end
method_added(meth) click to toggle source

Clear the #setter_methods cache when a setter method is added

Calls superclass method
# File lib/sequel/model/base.rb, line 539
def method_added(meth)
  clear_setter_methods_cache if meth.to_s =~ SETTER_METHOD_REGEXP
  super
end
no_primary_key() click to toggle source

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
# File lib/sequel/model/base.rb, line 550
def no_primary_key
  clear_setter_methods_cache
  self.simple_pk = @primary_key = nil
end
plugin(plugin, *args, &block) click to toggle source

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.

# File lib/sequel/model/base.rb, line 560
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
prepared_finder(meth=OPTS, opts=OPTS, &block) click to toggle source

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

# File lib/sequel/model/base.rb, line 626
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
primary_key_hash(value) click to toggle source

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}
# File lib/sequel/model/base.rb, line 582
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
qualified_primary_key_hash(value, qualifier=table_name) click to toggle source

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)
# File lib/sequel/model/base.rb, line 602
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
restrict_primary_key() click to toggle source

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.

# File lib/sequel/model/base.rb, line 639
def restrict_primary_key
  clear_setter_methods_cache
  @restrict_primary_key = true
end
restrict_primary_key?() click to toggle source

Whether or not setting the primary key(s) when using mass assignment (e.g. set) is restricted, true by default.

# File lib/sequel/model/base.rb, line 646
def restrict_primary_key?
  @restrict_primary_key
end
set_allowed_columns(*cols) click to toggle source

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
# File lib/sequel/model/base.rb, line 661
def set_allowed_columns(*cols)
  clear_setter_methods_cache
  @allowed_columns = cols
end
set_dataset(ds, opts=OPTS) click to toggle source

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.

# File lib/sequel/model/base.rb, line 686
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 = @dataset.columns rescue nil
  else
    @dataset_method_modules.each{|m| @dataset.extend(m)} if @dataset_method_modules
  end
  @dataset.model = self if @dataset.respond_to?(:model=)
  check_non_connection_error{@db_schema = (inherited ? superclass.db_schema : get_db_schema)}
  reset_instance_dataset
  self
end
set_primary_key(key) click to toggle source

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
# File lib/sequel/model/base.rb, line 716
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
setter_methods() click to toggle source

Cache of setter methods to allow by default, in order to speed up new/set/update instance methods.

# File lib/sequel/model/base.rb, line 732
def setter_methods
  @setter_methods ||= get_setter_methods
end
subset(name, *args, &block) click to toggle source

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.

# File lib/sequel/model/base.rb, line 758
def subset(name, *args, &block)
  dataset_module.subset(name, *args, &block)
end
table_name() click to toggle source

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
# File lib/sequel/model/base.rb, line 768
def table_name
  dataset.first_source_alias
end
unrestrict_primary_key() click to toggle source

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
# File lib/sequel/model/base.rb, line 778
def unrestrict_primary_key
  clear_setter_methods_cache
  @restrict_primary_key = false
end
with_pk(pk) click to toggle source

Return the model instance with the primary key, or nil if there is no matching record.

# File lib/sequel/model/base.rb, line 784
def with_pk(pk)
  primary_key_lookup(pk)
end
with_pk!(pk) click to toggle source

Return the model instance with the primary key, or raise NoMatchingRow if there is no matching record.

# File lib/sequel/model/base.rb, line 789
def with_pk!(pk)
  with_pk(pk) || raise(NoMatchingRow)
end

Private Instance Methods

check_non_connection_error() { || ... } click to toggle source

Yield to the passed block and swallow all errors other than DatabaseConnectionErrors.

# File lib/sequel/model/base.rb, line 799
def check_non_connection_error
  begin
    yield
  rescue Sequel::DatabaseConnectionError
    raise
  rescue
    nil
  end
end
convert_input_dataset(ds) click to toggle source

Convert the given object to a Dataset that should be used as this model's dataset.

# File lib/sequel/model/base.rb, line 811
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
dataset_extend(mod, opts=OPTS) click to toggle source

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.

# File lib/sequel/model/base.rb, line 831
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
def_bad_column_accessor(column) click to toggle source

Create a column accessor for a column with a method name that is hard to use in ruby code.

# File lib/sequel/model/base.rb, line 841
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
def_column_accessor(*columns) click to toggle source

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.

# File lib/sequel/model/base.rb, line 850
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{|x| x.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
def_finder_method(mod, meth, type) click to toggle source

Define a finder method in the given module with the given method name that load rows using the finder with the given name.

# File lib/sequel/model/base.rb, line 877
def def_finder_method(mod, meth, type)
  mod.send(:define_method, meth){|*args, &block| finder_for(meth).send(type, *args, &block)}
end
def_model_dataset_method(meth) click to toggle source

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.

# File lib/sequel/model/base.rb, line 865
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
def_prepare_method(mod, meth) click to toggle source

Define a #prepared_finder method in the given module that will call the associated prepared statement.

# File lib/sequel/model/base.rb, line 883
def def_prepare_method(mod, meth)
  mod.send(:define_method, meth){|*args, &block| finder_for(meth).call(prepare_method_arg_hash(args), &block)}
end
finder_for(meth) click to toggle source

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.

# File lib/sequel/model/base.rb, line 890
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_db_schema(reload = reload_db_schema?) click to toggle source

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.

# File lib/sequel/model/base.rb, line 902
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
get_setter_methods() click to toggle source

Uncached version of #setter_methods, to be overridden by plugins that want to modify the methods used.

# File lib/sequel/model/base.rb, line 947
def get_setter_methods
  if allowed_columns
    allowed_columns.map{|x| "#{x}="}
  else
    meths = instance_methods.collect{|x| x.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
inherited_instance_variables() click to toggle source

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.

# File lib/sequel/model/base.rb, line 961
def inherited_instance_variables
  INHERITED_INSTANCE_VARIABLES.dup
end
late_binding_class_option(opts, default) click to toggle source

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.

# File lib/sequel/model/base.rb, line 969
def late_binding_class_option(opts, default)
  case opts[:class]
    when String, Symbol
      # Delete :class to allow late binding
      opts[:class_name] ||= opts.delete(:class).to_s
    when Class
      opts[:class_name] ||= opts[:class].name
  end
  opts[:class_name] ||= ((name || '').split("::")[0..-2] + [camelize(default)]).join('::')
end
overridable_methods_module() click to toggle source

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.

# File lib/sequel/model/base.rb, line 982
def overridable_methods_module
  include(@overridable_methods_module = Module.new) unless @overridable_methods_module
  @overridable_methods_module
end
plugin_module(plugin) click to toggle source

Returns the module for the specified plugin. If the module is not defined, the corresponding plugin required.

# File lib/sequel/model/base.rb, line 989
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
plugin_module_defined?(plugin, submod) click to toggle source

Check if the plugin module plugin defines the constant named by submod.

# File lib/sequel/model/base.rb, line 1009
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
prepare_method_arg_hash(args) click to toggle source

An hash of prepared argument values for the given arguments, with keys starting at a. Used by the methods created by prepared_finder.

# File lib/sequel/model/base.rb, line 1021
def prepare_method_arg_hash(args)
  h = {}
  prepare_method_args('a', args.length).zip(args).each{|k, v| h[k] = v}
  h
end
prepare_method_args(base, n) click to toggle source

An array of prepared statement argument names, of length n and starting with base.

# File lib/sequel/model/base.rb, line 1028
def prepare_method_args(base, n)
  (0...n).map do
    s = base.to_sym
    base = base.next
    s
  end
end
primary_key_lookup(pk) click to toggle source

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.

# File lib/sequel/model/base.rb, line 1042
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
reload_db_schema?() click to toggle source

Whether to reload the database schema by default, ignoring any cached value.

# File lib/sequel/model/base.rb, line 1057
def reload_db_schema?
  false
end
reset_fast_pk_lookup_sql() click to toggle source

Reset the cached fast primary lookup SQL if a simple table and primary key are used, or set it to nil if not used.

# File lib/sequel/model/base.rb, line 1063
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_instance_dataset() click to toggle source

Reset the instance dataset to a modified copy of the current dataset, should be used whenever the model's dataset is modified.

# File lib/sequel/model/base.rb, line 1074
def reset_instance_dataset
  @finders.clear if @finders
  @instance_dataset = @dataset.limit(1).naked if @dataset
end
set_columns(new_columns) click to toggle source

Set the columns for this model and create accessor methods for each column.

# File lib/sequel/model/base.rb, line 1080
def set_columns(new_columns)
  @columns = new_columns
  def_column_accessor(*new_columns) if new_columns
  @columns
end
set_dataset_row_proc(ds) click to toggle source

Set the dataset's row_proc to the current model.

# File lib/sequel/model/base.rb, line 1087
def set_dataset_row_proc(ds)
  ds.row_proc = self
end
simple_pk=(pk) click to toggle source

Reset the fast primary key lookup SQL when the #simple_pk value changes.

# File lib/sequel/model/base.rb, line 1092
def simple_pk=(pk)
  @simple_pk = pk
  reset_fast_pk_lookup_sql
end
simple_table=(t) click to toggle source

Reset the fast primary key lookup SQL when the #simple_table value changes.

# File lib/sequel/model/base.rb, line 1098
def simple_table=(t)
  @simple_table = t
  reset_fast_pk_lookup_sql
end