module Sequel::Model::Associations::ClassMethods

Each kind of association adds a number of instance methods to the model class which are specialized according to the association type and optional parameters given in the definition. Example:

class Project < Sequel::Model
  many_to_one :portfolio
  # or: one_to_one :portfolio
  one_to_many :milestones
  # or: many_to_many :milestones
end

The project class now has the following instance methods:

portfolio

Returns the associated portfolio.

portfolio=(obj)

Sets the associated portfolio to the object, but the change is not persisted until you save the record (for many_to_one associations).

portfolio_dataset

Returns a dataset that would return the associated portfolio, only useful in fairly specific circumstances.

milestones

Returns an array of associated milestones

add_milestone(obj)

Associates the passed milestone with this object.

remove_milestone(obj)

Removes the association with the passed milestone.

remove_all_milestones

Removes associations with all associated milestones.

milestones_dataset

Returns a dataset that would return the associated milestones, allowing for further filtering/limiting/etc.

If you want to override the behavior of the add_/remove_/remove_all_/ methods or the association setter method, use the :adder, :remover, :clearer, and/or :setter options. These options override the default behavior.

By default the classes for the associations are inferred from the association name, so for example the Project#portfolio will return an instance of Portfolio, and Project#milestones will return an array of Milestone instances. You can use the :class option to change which class is used.

Association definitions are also reflected by the class, e.g.:

Project.associations
=> [:portfolio, :milestones]
Project.association_reflection(:portfolio)
=> #<Sequel::Model::Associations::ManyToOneAssociationReflection Project.many_to_one :portfolio>

Associations should not have the same names as any of the columns in the model's current table they reference. If you are dealing with an existing schema that has a column named status, you can't name the association status, you'd have to name it foo_status or something else. If you give an association the same name as a column, you will probably end up with an association that doesn't work, or a SystemStackError.

For a more in depth general overview, as well as a reference guide, see the Association Basics guide. For examples of advanced usage, see the Advanced Associations guide.

Attributes

association_reflections[R]

All association reflections defined for this model (default: {}).

autoreloading_associations[R]

Hash with column symbol keys and arrays of many_to_one association symbols that should be cleared when the column value changes.

cache_associations[RW]

Whether association metadata should be cached in the association reflection. If not cached, it will be computed on demand. In general you only want to set this to false when using code reloading. When using code reloading, setting this will make sure that if an associated class is removed or modified, this class will not have a reference to the previous class.

default_association_options[RW]

The default options to use for all associations. This hash is merged into the association reflection hash for all association reflections.

default_association_type_options[RW]

The default options to use for all associations of a given type. This is a hash keyed by association type symbol. If there is a value for the association type symbol key, the resulting hash will be merged into the association reflection hash for all association reflections of that type.

default_eager_limit_strategy[RW]

The default :eager_limit_strategy option to use for limited or offset associations (default: true, causing Sequel to use what it considers the most appropriate strategy).

Public Instance Methods

all_association_reflections() click to toggle source

Array of all association reflections for this model class

     # File lib/sequel/model/associations.rb
1563 def all_association_reflections
1564   association_reflections.values
1565 end
associate(type, name, opts = OPTS, &block) click to toggle source

Associates a related model with the current model. The following types are supported:

:many_to_one

Foreign key in current model's table points to associated model's primary key. Each associated model object can be associated with more than one current model objects. Each current model object can be associated with only one associated model object.

:one_to_many

Foreign key in associated model's table points to this model's primary key. Each current model object can be associated with more than one associated model objects. Each associated model object can be associated with only one current model object.

:one_through_one

Similar to many_to_many in terms of foreign keys, but only one object is associated to the current object through the association. Provides only getter methods, no setter or modification methods.

:one_to_one

Similar to one_to_many in terms of foreign keys, but only one object is associated to the current object through the association. The methods created are similar to many_to_one, except that the one_to_one setter method saves the passed object.

:many_to_many

A join table is used that has a foreign key that points to this model's primary key and a foreign key that points to the associated model's primary key. Each current model object can be associated with many associated model objects, and each associated model object can be associated with many current model objects.

The following options can be supplied:

Multiple Types

:adder

Proc used to define the private add* method for doing the database work to associate the given object to the current object (*_to_many assocations).

:after_add

Symbol, Proc, or array of both/either specifying a callback to call after a new item is added to the association.

:after_load

Symbol, Proc, or array of both/either specifying a callback to call after the associated record(s) have been retrieved from the database.

:after_remove

Symbol, Proc, or array of both/either specifying a callback to call after an item is removed from the association.

:after_set

Symbol, Proc, or array of both/either specifying a callback to call after an item is set using the association setter method.

:allow_eager

If set to false, you cannot load the association eagerly via eager or eager_graph

:before_add

Symbol, Proc, or array of both/either specifying a callback to call before a new item is added to the association.

:before_remove

Symbol, Proc, or array of both/either specifying a callback to call before an item is removed from the association.

:before_set

Symbol, Proc, or array of both/either specifying a callback to call before an item is set using the association setter method.

:cartesian_product_number

the number of joins completed by this association that could cause more than one row for each row in the current table (default: 0 for many_to_one, one_to_one, and one_through_one associations, 1 for one_to_many and many_to_many associations).

:class

The associated class or its name as a string or symbol. If not given, uses the association's name, which is camelized (and singularized unless the type is :many_to_one, :one_to_one, or one_through_one). If this is specified as a string or symbol, you must specify the full class name (e.g. “::SomeModule::MyModel”).

:class_namespace

If :class is given as a string or symbol, sets the default namespace in which to look for the class. class: 'Foo', class_namespace: 'Bar' looks for ::Bar::Foo.)

:clearer

Proc used to define the private remove_all* method for doing the database work to remove all objects associated to the current object (*_to_many assocations).

:clone

Merge the current options and block into the options and block used in defining the given association. Can be used to DRY up a bunch of similar associations that all share the same options such as :class and :key, while changing the order and block used.

:conditions

The conditions to use to filter the association, can be any argument passed to where. This option is not respected when using eager_graph or association_join, unless it is hash or array of two element arrays. Consider also specifying the :graph_block option if the value for this option is not a hash or array of two element arrays and you plan to use this association in eager_graph or association_join.

:dataset

A proc that is used to define the method to get the base dataset to use (before the other options are applied). If the proc accepts an argument, it is passed the related association reflection. It is a best practice to always have the dataset accept an argument and use the argument to return the appropriate dataset.

:distinct

Use the DISTINCT clause when selecting associating object, both when lazy loading and eager loading via .eager (but not when using .eager_graph).

:eager

The associations to eagerly load via eager when loading the associated object(s).

:eager_block

If given, use the block instead of the default block when eagerly loading. To not use a block when eager loading (when one is used normally), set to nil.

:eager_graph

The associations to eagerly load via eager_graph when loading the associated object(s). many_to_many associations with this option cannot be eagerly loaded via eager.

:eager_grapher

A proc to use to implement eager loading via eager_graph, overriding the default. Takes an options hash with at least the entries :self (the receiver of the eager_graph call), :table_alias (the alias to use for table to graph into the association), and :implicit_qualifier (the alias that was used for the current table). Should return a copy of the dataset with the association graphed into it.

:eager_limit_strategy

Determines the strategy used for enforcing limits and offsets when eager loading associations via the eager method.

:eager_loader

A proc to use to implement eager loading, overriding the default. Takes a single hash argument, with at least the keys: :rows, which is an array of current model instances, :associations, which is a hash of dependent associations, :self, which is the dataset doing the eager loading, :eager_block, which is a dynamic callback that should be called with the dataset, and :id_map, which is a mapping of key values to arrays of current model instances. In the proc, the associated records should be queried from the database and the associations cache for each record should be populated.

:eager_loader_key

A symbol for the key column to use to populate the key_hash for the eager loader. Can be set to nil to not populate the key_hash.

:extend

A module or array of modules to extend the dataset with.

:filter_limit_strategy

Determines the strategy used for enforcing limits and offsets when filtering by limited associations. Possible options are :window_function, :distinct_on, or :correlated_subquery depending on association type and database type.

:graph_alias_base

The base name to use for the table alias when eager graphing. Defaults to the name of the association. If the alias name has already been used in the query, Sequel will create a unique alias by appending a numeric suffix (e.g. alias_0, alias_1, …) until the alias is unique.

:graph_block

The block to pass to join_table when eagerly loading the association via eager_graph.

:graph_conditions

The additional conditions to use on the SQL join when eagerly loading the association via eager_graph. Should be a hash or an array of two element arrays. If not specified, the :conditions option is used if it is a hash or array of two element arrays.

:graph_join_type

The type of SQL join to use when eagerly loading the association via eager_graph. Defaults to :left_outer.

:graph_only_conditions

The conditions to use on the SQL join when eagerly loading the association via eager_graph, instead of the default conditions specified by the foreign/primary keys. This option causes the :graph_conditions option to be ignored.

:graph_order

Over the order to use when using eager_graph, instead of the default order. This should be used in the case where :order contains an identifier qualified by the table's name, which may not match the alias used when eager graphing. By setting this to the unqualified identifier, it will be automatically qualified when using eager_graph.

:graph_select

A column or array of columns to select from the associated table when eagerly loading the association via eager_graph. Defaults to all columns in the associated table.

:limit

Limit the number of records to the provided value. Use an array with two elements for the value to specify a limit (first element) and an offset (second element).

:methods_module

The module that methods the association creates will be placed into. Defaults to the module containing the model's columns.

:order

the column(s) by which to order the association dataset. Can be a singular column symbol or an array of column symbols.

:order_eager_graph

Whether to add the association's order to the graphed dataset's order when graphing via eager_graph. Defaults to true, so set to false to disable.

:read_only

Do not add a setter method (for many_to_one or one_to_one associations), or add_/remove_/remove_all_ methods (for one_to_many and many_to_many associations).

:reciprocal

the symbol name of the reciprocal association, if it exists. By default, Sequel will try to determine it by looking at the associated model's assocations for a association that matches the current association's key(s). Set to nil to not use a reciprocal.

:remover

Proc used to define the private remove* method for doing the database work to remove the association between the given object and the current object (*_to_many assocations).

:select

the columns to select. Defaults to the associated class's table_name.* in an association that uses joins, which means it doesn't include the attributes from the join table. If you want to include the join table attributes, you can use this option, but beware that the join table attributes can clash with attributes from the model table, so you should alias any attributes that have the same name in both the join table and the associated table.

:setter

Proc used to define the private _*= method for doing the work to setup the assocation between the given object and the current object (*_to_one associations).

:subqueries_per_union

The number of subqueries to use in each UNION query, for eager loading limited associations using the default :union strategy.

:validate

Set to false to not validate when implicitly saving any associated object.

:many_to_one

:key

foreign key in current model's table that references associated model's primary key, as a symbol. Defaults to :“#{name}_id”. Can use an array of symbols for a composite key association.

:key_column

Similar to, and usually identical to, :key, but :key refers to the model method to call, where :key_column refers to the underlying column. Should only be used if the model method differs from the foreign key column, in conjunction with defining a model alias method for the key column.

:primary_key

column in the associated table that :key option references, as a symbol. Defaults to the primary key of the associated table. Can use an array of symbols for a composite key association.

:primary_key_method

the method symbol or array of method symbols to call on the associated object to get the foreign key values. Defaults to :primary_key option.

:qualify

Whether to use qualified primary keys when loading the association. The default is true, so you must set to false to not qualify. Qualification rarely causes problems, but it's necessary to disable in some cases, such as when you are doing a JOIN USING operation on the column on Oracle.

:one_to_many and :one_to_one

:key

foreign key in associated model's table that references current model's primary key, as a symbol. Defaults to :“#{self.name.underscore}_id”. Can use an array of symbols for a composite key association.

:key_method

the method symbol or array of method symbols to call on the associated object to get the foreign key values. Defaults to :key option.

:primary_key

column in the current table that :key option references, as a symbol. Defaults to primary key of the current table. Can use an array of symbols for a composite key association.

:primary_key_column

Similar to, and usually identical to, :primary_key, but :primary_key refers to the model method call, where :primary_key_column refers to the underlying column. Should only be used if the model method differs from the primary key column, in conjunction with defining a model alias method for the primary key column.

:raise_on_save_failure

Do not raise exceptions for hook or validation failures when saving associated objects in the add/remove methods (return nil instead) [one_to_many only].

:many_to_many and :one_through_one

:graph_join_table_block

The block to pass to join_table for the join table when eagerly loading the association via eager_graph.

:graph_join_table_conditions

The additional conditions to use on the SQL join for the join table when eagerly loading the association via eager_graph. Should be a hash or an array of two element arrays.

:graph_join_table_join_type

The type of SQL join to use for the join table when eagerly loading the association via eager_graph. Defaults to the :graph_join_type option or :left_outer.

:graph_join_table_only_conditions

The conditions to use on the SQL join for the join table when eagerly loading the association via eager_graph, instead of the default conditions specified by the foreign/primary keys. This option causes the :graph_join_table_conditions option to be ignored.

:join_table

name of table that includes the foreign keys to both the current model and the associated model, as a symbol. Defaults to the name of current model and name of associated model, pluralized, underscored, sorted, and joined with '_'.

:join_table_block

proc that can be used to modify the dataset used in the add/remove/remove_all methods. Should accept a dataset argument and return a modified dataset if present.

:left_key

foreign key in join table that points to current model's primary key, as a symbol. Defaults to :“#{self.name.underscore}_id”. Can use an array of symbols for a composite key association.

:left_primary_key

column in current table that :left_key points to, as a symbol. Defaults to primary key of current table. Can use an array of symbols for a composite key association.

:left_primary_key_column

Similar to, and usually identical to, :left_primary_key, but :left_primary_key refers to the model method to call, where :left_primary_key_column refers to the underlying column. Should only be used if the model method differs from the left primary key column, in conjunction with defining a model alias method for the left primary key column.

:right_key

foreign key in join table that points to associated model's primary key, as a symbol. Defaults to :“#{name.to_s.singularize}_id”. Can use an array of symbols for a composite key association.

:right_primary_key

column in associated table that :right_key points to, as a symbol. Defaults to primary key of the associated table. Can use an array of symbols for a composite key association.

:right_primary_key_method

the method symbol or array of method symbols to call on the associated object to get the foreign key values for the join table. Defaults to :right_primary_key option.

:uniq

Adds a after_load callback that makes the array of objects unique.

     # File lib/sequel/model/associations.rb
1785 def associate(type, name, opts = OPTS, &block)
1786   raise(Error, 'invalid association type') unless assoc_class = Sequel.synchronize{ASSOCIATION_TYPES[type]}
1787   raise(Error, 'Model.associate name argument must be a symbol') unless name.is_a?(Symbol)
1788 
1789   # dup early so we don't modify opts
1790   orig_opts = opts.dup
1791 
1792   if opts[:clone]
1793     cloned_assoc = association_reflection(opts[:clone])
1794     orig_opts = cloned_assoc[:orig_opts].merge(orig_opts)
1795   end
1796 
1797   opts = Hash[default_association_options]
1798   if type_options = default_association_type_options[type]
1799     opts.merge!(type_options)
1800   end
1801   opts.merge!(orig_opts)
1802   opts.merge!(:type => type, :name => name, :cache=>({} if cache_associations), :model => self)
1803 
1804   opts[:block] = block if block
1805   opts[:instance_specific] = true if orig_opts[:dataset]
1806   if !opts.has_key?(:instance_specific) && (block || orig_opts[:block])
1807     # It's possible the association is instance specific, in that it depends on
1808     # values other than the foreign key value.  This needs to be checked for
1809     # in certain places to disable optimizations.
1810     opts[:instance_specific] = _association_instance_specific_default(name)
1811   end
1812   opts = assoc_class.new.merge!(opts)
1813 
1814   if opts[:clone] && !opts.cloneable?(cloned_assoc)
1815     raise(Error, "cannot clone an association to an association of different type (association #{name} with type #{type} cloning #{opts[:clone]} with type #{cloned_assoc[:type]})")
1816   end
1817 
1818   opts[:use_placeholder_loader] = !opts[:instance_specific] && !opts[:eager_graph]
1819   opts[:eager_block] = opts[:block] unless opts.include?(:eager_block)
1820   opts[:graph_join_type] ||= :left_outer
1821   opts[:order_eager_graph] = true unless opts.include?(:order_eager_graph)
1822   conds = opts[:conditions]
1823   opts[:graph_alias_base] ||= name
1824   opts[:graph_conditions] = conds if !opts.include?(:graph_conditions) and Sequel.condition_specifier?(conds)
1825   opts[:graph_conditions] = opts.fetch(:graph_conditions, []).to_a
1826   opts[:graph_select] = Array(opts[:graph_select]) if opts[:graph_select]
1827   [:before_add, :before_remove, :after_add, :after_remove, :after_load, :before_set, :after_set].each do |cb_type|
1828     opts[cb_type] = Array(opts[cb_type]) if opts[cb_type]
1829   end
1830 
1831   if opts[:extend]
1832     opts[:extend] = Array(opts[:extend])
1833     opts[:reverse_extend] = opts[:extend].reverse
1834   end
1835 
1836   late_binding_class_option(opts, opts.returns_array? ? singularize(name) : name)
1837   
1838   # Remove :class entry if it exists and is nil, to work with cached_fetch
1839   opts.delete(:class) unless opts[:class]
1840 
1841   send(:"def_#{type}", opts)
1842   def_association_instance_methods(opts)
1843       
1844   orig_opts.delete(:clone)
1845   opts[:orig_class] = orig_opts[:class] || orig_opts[:class_name]
1846   orig_opts.merge!(:class_name=>opts[:class_name], :class=>opts[:class], :block=>opts[:block])
1847   opts[:orig_opts] = orig_opts
1848   # don't add to association_reflections until we are sure there are no errors
1849   association_reflections[name] = opts
1850 end
association_reflection(name) click to toggle source

The association reflection hash for the association of the given name.

     # File lib/sequel/model/associations.rb
1853 def association_reflection(name)
1854   association_reflections[name]
1855 end
associations() click to toggle source

Array of association name symbols

     # File lib/sequel/model/associations.rb
1858 def associations
1859   association_reflections.keys
1860 end
eager_load_results(opts, eo, &block) click to toggle source

Eager load the association with the given eager loader options.

     # File lib/sequel/model/associations.rb
1863 def eager_load_results(opts, eo, &block)
1864   opts.eager_load_results(eo, &block)
1865 end
finalize_associations() click to toggle source

Finalize all associations such that values that are looked up dynamically in associated classes are set statically. As this modifies the associations, it must be done before calling freeze.

     # File lib/sequel/model/associations.rb
1882 def finalize_associations
1883   @association_reflections.each_value(&:finalize)
1884 end
freeze() click to toggle source

Freeze association related metadata when freezing model class.

Calls superclass method
     # File lib/sequel/model/associations.rb
1868 def freeze
1869   @association_reflections.freeze.each_value(&:freeze)
1870   @autoreloading_associations.freeze.each_value(&:freeze)
1871   @default_association_options.freeze
1872   @default_association_type_options.freeze
1873   @default_association_type_options.each_value(&:freeze)
1874 
1875   super
1876 end
many_to_many(name, opts=OPTS, &block) click to toggle source

Shortcut for adding a many_to_many association, see associate

     # File lib/sequel/model/associations.rb
1887 def many_to_many(name, opts=OPTS, &block)
1888   associate(:many_to_many, name, opts, &block)
1889 end
many_to_one(name, opts=OPTS, &block) click to toggle source

Shortcut for adding a many_to_one association, see associate

     # File lib/sequel/model/associations.rb
1892 def many_to_one(name, opts=OPTS, &block)
1893   associate(:many_to_one, name, opts, &block)
1894 end
one_through_one(name, opts=OPTS, &block) click to toggle source

Shortcut for adding a one_through_one association, see associate

     # File lib/sequel/model/associations.rb
1897 def one_through_one(name, opts=OPTS, &block)
1898   associate(:one_through_one, name, opts, &block)
1899 end
one_to_many(name, opts=OPTS, &block) click to toggle source

Shortcut for adding a one_to_many association, see associate

     # File lib/sequel/model/associations.rb
1902 def one_to_many(name, opts=OPTS, &block)
1903   associate(:one_to_many, name, opts, &block)
1904 end
one_to_one(name, opts=OPTS, &block) click to toggle source

Shortcut for adding a one_to_one association, see associate

     # File lib/sequel/model/associations.rb
1907 def one_to_one(name, opts=OPTS, &block)
1908   associate(:one_to_one, name, opts, &block)
1909 end

Private Instance Methods

_association_instance_specific_default(_) click to toggle source

The default value for the instance_specific option, if the association could be instance specific and the :instance_specific option is not specified.

     # File lib/sequel/model/associations.rb
1918 def _association_instance_specific_default(_)
1919   true
1920 end
association_module(opts=OPTS) click to toggle source

The module to use for the association's methods. Defaults to the overridable_methods_module.

     # File lib/sequel/model/associations.rb
1924 def association_module(opts=OPTS)
1925   opts.fetch(:methods_module, overridable_methods_module)
1926 end
association_module_def(name, opts=OPTS, &block) click to toggle source

Add a method to the module included in the class, so the method can be easily overridden in the class itself while allowing for super to be called.

     # File lib/sequel/model/associations.rb
1931 def association_module_def(name, opts=OPTS, &block)
1932   association_module(opts).send(:define_method, name, &block)
1933   association_module(opts).send(:alias_method, name, name)
1934 end
association_module_private_def(name, opts=OPTS, &block) click to toggle source

Add a private method to the module included in the class.

     # File lib/sequel/model/associations.rb
1937 def association_module_private_def(name, opts=OPTS, &block)
1938   association_module_def(name, opts, &block)
1939   association_module(opts).send(:private, name)
1940 end
def_association_instance_methods(opts) click to toggle source

Define all of the association instance methods for this association.

     # File lib/sequel/model/associations.rb
1950 def def_association_instance_methods(opts)
1951   # Always set the method names in the association reflection, even if they
1952   # are not used, for backwards compatibility.
1953   opts[:dataset_method] = :"#{opts[:name]}_dataset"
1954   if opts.returns_array?
1955     sname = singularize(opts[:name])
1956     opts[:_add_method] = :"_add_#{sname}"
1957     opts[:add_method] = :"add_#{sname}"
1958     opts[:_remove_method] = :"_remove_#{sname}"
1959     opts[:remove_method] = :"remove_#{sname}"
1960     opts[:_remove_all_method] = :"_remove_all_#{opts[:name]}"
1961     opts[:remove_all_method] = :"remove_all_#{opts[:name]}"
1962   else
1963     opts[:_setter_method] = :"_#{opts[:name]}="
1964     opts[:setter_method] = :"#{opts[:name]}="
1965   end
1966 
1967   association_module_def(opts.dataset_method, opts){_dataset(opts)}
1968   if opts[:block]
1969     opts[:block_method] = Plugins.def_sequel_method(association_module(opts), "#{opts[:name]}_block", 1, &opts[:block])
1970   end
1971   opts[:dataset_opt_arity] = opts[:dataset].arity == 0 ? 0 : 1
1972   opts[:dataset_opt_method] = Plugins.def_sequel_method(association_module(opts), "#{opts[:name]}_dataset_opt", opts[:dataset_opt_arity], &opts[:dataset])
1973   def_association_method(opts)
1974 
1975   return if opts[:read_only]
1976 
1977   if opts[:setter] && opts[:_setter]
1978     # This is backwards due to backwards compatibility
1979     association_module_private_def(opts[:_setter_method], opts, &opts[:setter])
1980     association_module_def(opts[:setter_method], opts, &opts[:_setter])
1981   end
1982 
1983   if adder = opts[:adder]
1984     association_module_private_def(opts[:_add_method], opts, &adder)
1985     association_module_def(opts[:add_method], opts){|o,*args| add_associated_object(opts, o, *args)}
1986   end
1987 
1988   if remover = opts[:remover]
1989     association_module_private_def(opts[:_remove_method], opts, &remover)
1990     association_module_def(opts[:remove_method], opts){|o,*args| remove_associated_object(opts, o, *args)}
1991   end
1992 
1993   if clearer = opts[:clearer]
1994     association_module_private_def(opts[:_remove_all_method], opts, &clearer)
1995     association_module_def(opts[:remove_all_method], opts){|*args| remove_all_associated_objects(opts, *args)}
1996   end
1997 end
def_association_method(opts) click to toggle source

Adds the association method to the association methods module.

     # File lib/sequel/model/associations.rb
1943 def def_association_method(opts)
1944   association_module_def(opts.association_method, opts) do |dynamic_opts=OPTS, &block|
1945     load_associated_objects(opts, dynamic_opts, &block)
1946   end
1947 end
def_many_to_many(opts) click to toggle source

Configures many_to_many and one_through_one association reflection and adds the related association methods

     # File lib/sequel/model/associations.rb
2000 def def_many_to_many(opts)
2001   one_through_one = opts[:type] == :one_through_one
2002   left = (opts[:left_key] ||= opts.default_left_key)
2003   lcks = opts[:left_keys] = Array(left)
2004   right = (opts[:right_key] ||= opts.default_right_key)
2005   rcks = opts[:right_keys] = Array(right)
2006   left_pk = (opts[:left_primary_key] ||= self.primary_key)
2007   opts[:eager_loader_key] = left_pk unless opts.has_key?(:eager_loader_key)
2008   lcpks = opts[:left_primary_keys] = Array(left_pk)
2009   lpkc = opts[:left_primary_key_column] ||= left_pk
2010   lpkcs = opts[:left_primary_key_columns] ||= Array(lpkc)
2011   raise(Error, "mismatched number of left keys: #{lcks.inspect} vs #{lcpks.inspect}") unless lcks.length == lcpks.length
2012   if opts[:right_primary_key]
2013     rcpks = Array(opts[:right_primary_key])
2014     raise(Error, "mismatched number of right keys: #{rcks.inspect} vs #{rcpks.inspect}") unless rcks.length == rcpks.length
2015   end
2016   opts[:uses_left_composite_keys] = lcks.length > 1
2017   opts[:uses_right_composite_keys] = rcks.length > 1
2018   opts[:cartesian_product_number] ||= one_through_one ? 0 : 1
2019   join_table = (opts[:join_table] ||= opts.default_join_table)
2020   opts[:left_key_alias] ||= opts.default_associated_key_alias
2021   opts[:graph_join_table_join_type] ||= opts[:graph_join_type]
2022   if opts[:uniq]
2023     opts[:after_load] ||= []
2024     opts[:after_load].unshift(:array_uniq!)
2025   end
2026   opts[:dataset] ||= opts.association_dataset_proc
2027   opts[:eager_loader] ||= opts.method(:default_eager_loader)
2028   
2029   join_type = opts[:graph_join_type]
2030   select = opts[:graph_select]
2031   use_only_conditions = opts.include?(:graph_only_conditions)
2032   only_conditions = opts[:graph_only_conditions]
2033   conditions = opts[:graph_conditions]
2034   graph_block = opts[:graph_block]
2035   graph_jt_conds = opts[:graph_join_table_conditions] = opts.fetch(:graph_join_table_conditions, []).to_a
2036   use_jt_only_conditions = opts.include?(:graph_join_table_only_conditions)
2037   jt_only_conditions = opts[:graph_join_table_only_conditions]
2038   jt_join_type = opts[:graph_join_table_join_type]
2039   jt_graph_block = opts[:graph_join_table_block]
2040   opts[:eager_grapher] ||= proc do |eo|
2041     ds = eo[:self]
2042     egls = eo[:limit_strategy]
2043     if egls && egls != :ruby
2044       associated_key_array = opts.associated_key_array
2045       orig_egds = egds = eager_graph_dataset(opts, eo)
2046       egds = egds.
2047         inner_join(join_table, rcks.zip(opts.right_primary_keys) + graph_jt_conds, :qualify=>:deep).
2048         select_all(egds.first_source).
2049         select_append(*associated_key_array)
2050       egds = opts.apply_eager_graph_limit_strategy(egls, egds)
2051       ds.graph(egds, associated_key_array.map(&:alias).zip(lpkcs) + conditions, :qualify=>:deep, :table_alias=>eo[:table_alias], :implicit_qualifier=>eo[:implicit_qualifier], :join_type=>eo[:join_type]||join_type, :from_self_alias=>eo[:from_self_alias], :join_only=>eo[:join_only], :select=>select||orig_egds.columns, &graph_block)
2052     else
2053       ds = ds.graph(join_table, use_jt_only_conditions ? jt_only_conditions : lcks.zip(lpkcs) + graph_jt_conds, :select=>false, :table_alias=>ds.unused_table_alias(join_table, [eo[:table_alias]]), :join_type=>eo[:join_type]||jt_join_type, :join_only=>eo[:join_only], :implicit_qualifier=>eo[:implicit_qualifier], :qualify=>:deep, :from_self_alias=>eo[:from_self_alias], &jt_graph_block)
2054       ds.graph(eager_graph_dataset(opts, eo), use_only_conditions ? only_conditions : opts.right_primary_keys.zip(rcks) + conditions, :select=>select, :table_alias=>eo[:table_alias], :qualify=>:deep, :join_type=>eo[:join_type]||join_type, :join_only=>eo[:join_only], &graph_block)
2055     end
2056   end
2057       
2058   return if opts[:read_only]
2059       
2060   if one_through_one
2061     opts[:setter] ||= proc do |o|
2062       h = {}
2063       lh = lcks.zip(lcpks.map{|k| get_column_value(k)})
2064       jtds = _join_table_dataset(opts).where(lh)
2065 
2066       checked_transaction do
2067         current = jtds.first
2068 
2069         if o
2070           new_values = []
2071           rcks.zip(opts.right_primary_key_methods).each{|k, pk| new_values << (h[k] = o.get_column_value(pk))}
2072         end
2073 
2074         if current
2075           current_values = rcks.map{|k| current[k]}
2076           jtds = jtds.where(rcks.zip(current_values))
2077           if o
2078             if current_values != new_values
2079               jtds.update(h)
2080             end
2081           else
2082             jtds.delete
2083           end
2084         elsif o
2085           lh.each{|k,v| h[k] = v}
2086           jtds.insert(h)
2087         end
2088       end
2089     end
2090     opts[:_setter] = proc{|o| set_one_through_one_associated_object(opts, o)}
2091   else 
2092     opts[:adder] ||= proc do |o|
2093       h = {}
2094       lcks.zip(lcpks).each{|k, pk| h[k] = get_column_value(pk)}
2095       rcks.zip(opts.right_primary_key_methods).each{|k, pk| h[k] = o.get_column_value(pk)}
2096       _join_table_dataset(opts).insert(h)
2097     end
2098 
2099     opts[:remover] ||= proc do |o|
2100       _join_table_dataset(opts).where(lcks.zip(lcpks.map{|k| get_column_value(k)}) + rcks.zip(opts.right_primary_key_methods.map{|k| o.get_column_value(k)})).delete
2101     end
2102 
2103     opts[:clearer] ||= proc do
2104       _join_table_dataset(opts).where(lcks.zip(lcpks.map{|k| get_column_value(k)})).delete
2105     end
2106   end
2107 end
def_many_to_one(opts) click to toggle source

Configures many_to_one association reflection and adds the related association methods

     # File lib/sequel/model/associations.rb
2110 def def_many_to_one(opts)
2111   name = opts[:name]
2112   opts[:key] = opts.default_key unless opts.has_key?(:key)
2113   key = opts[:key]
2114   opts[:eager_loader_key] = key unless opts.has_key?(:eager_loader_key)
2115   cks = opts[:graph_keys] = opts[:keys] = Array(key)
2116   opts[:key_column] ||= key
2117   opts[:graph_keys] = opts[:key_columns] = Array(opts[:key_column])
2118   opts[:qualified_key] = opts.qualify_cur(key)
2119   if opts[:primary_key]
2120     cpks = Array(opts[:primary_key])
2121     raise(Error, "mismatched number of keys: #{cks.inspect} vs #{cpks.inspect}") unless cks.length == cpks.length
2122   end
2123   uses_cks = opts[:uses_composite_keys] = cks.length > 1
2124   opts[:cartesian_product_number] ||= 0
2125 
2126   if !opts.has_key?(:many_to_one_pk_lookup) &&
2127      (opts[:dataset] || opts[:conditions] || opts[:block] || opts[:select] ||
2128       (opts.has_key?(:key) && opts[:key] == nil))
2129     opts[:many_to_one_pk_lookup] = false
2130   end
2131   auto_assocs = @autoreloading_associations
2132   cks.each do |k|
2133     (auto_assocs[k] ||= []) << name
2134   end
2135 
2136   opts[:dataset] ||= opts.association_dataset_proc
2137   opts[:eager_loader] ||= proc do |eo|
2138     h = eo[:id_map]
2139     pk_meths = opts.primary_key_methods
2140 
2141     eager_load_results(opts, eo) do |assoc_record|
2142       hash_key = uses_cks ? pk_meths.map{|k| assoc_record.get_column_value(k)} : assoc_record.get_column_value(opts.primary_key_method)
2143       h[hash_key].each{|object| object.associations[name] = assoc_record}
2144     end
2145   end
2146       
2147   join_type = opts[:graph_join_type]
2148   select = opts[:graph_select]
2149   use_only_conditions = opts.include?(:graph_only_conditions)
2150   only_conditions = opts[:graph_only_conditions]
2151   conditions = opts[:graph_conditions]
2152   graph_block = opts[:graph_block]
2153   graph_cks = opts[:graph_keys]
2154   opts[:eager_grapher] ||= proc do |eo|
2155     ds = eo[:self]
2156     ds.graph(eager_graph_dataset(opts, eo), use_only_conditions ? only_conditions : opts.primary_keys.zip(graph_cks) + conditions, eo.merge(:select=>select, :join_type=>eo[:join_type]||join_type, :qualify=>:deep), &graph_block)
2157   end
2158       
2159   return if opts[:read_only]
2160       
2161   opts[:setter] ||= proc{|o| cks.zip(opts.primary_key_methods).each{|k, pk| set_column_value(:"#{k}=", (o.get_column_value(pk) if o))}}
2162   opts[:_setter] = proc{|o| set_associated_object(opts, o)}
2163 end
def_one_through_one(opts) click to toggle source

Alias of def_many_to_many, since they share pretty much the same code.

     # File lib/sequel/model/associations.rb
2277 def def_one_through_one(opts)
2278   def_many_to_many(opts)
2279 end
def_one_to_many(opts) click to toggle source

Configures one_to_many and one_to_one association reflections and adds the related association methods

     # File lib/sequel/model/associations.rb
2166 def def_one_to_many(opts)
2167   one_to_one = opts[:type] == :one_to_one
2168   name = opts[:name]
2169   key = (opts[:key] ||= opts.default_key)
2170   km = opts[:key_method] ||= opts[:key]
2171   cks = opts[:keys] = Array(key)
2172   opts[:key_methods] = Array(opts[:key_method])
2173   primary_key = (opts[:primary_key] ||= self.primary_key)
2174   opts[:eager_loader_key] = primary_key unless opts.has_key?(:eager_loader_key)
2175   cpks = opts[:primary_keys] = Array(primary_key)
2176   pkc = opts[:primary_key_column] ||= primary_key
2177   pkcs = opts[:primary_key_columns] ||= Array(pkc)
2178   raise(Error, "mismatched number of keys: #{cks.inspect} vs #{cpks.inspect}") unless cks.length == cpks.length
2179   uses_cks = opts[:uses_composite_keys] = cks.length > 1
2180   opts[:dataset] ||= opts.association_dataset_proc
2181   opts[:eager_loader] ||= proc do |eo|
2182     h = eo[:id_map]
2183     reciprocal = opts.reciprocal
2184     assign_singular = opts.assign_singular?
2185     delete_rn = opts.delete_row_number_column
2186 
2187     eager_load_results(opts, eo) do |assoc_record|
2188       assoc_record.values.delete(delete_rn) if delete_rn
2189       hash_key = uses_cks ? km.map{|k| assoc_record.get_column_value(k)} : assoc_record.get_column_value(km)
2190       objects = h[hash_key]
2191       if assign_singular
2192         objects.each do |object| 
2193           unless object.associations[name]
2194             object.associations[name] = assoc_record
2195             assoc_record.associations[reciprocal] = object if reciprocal
2196           end
2197         end
2198       else
2199         objects.each do |object| 
2200           object.associations[name].push(assoc_record)
2201           assoc_record.associations[reciprocal] = object if reciprocal
2202         end
2203       end
2204     end
2205   end
2206   
2207   join_type = opts[:graph_join_type]
2208   select = opts[:graph_select]
2209   use_only_conditions = opts.include?(:graph_only_conditions)
2210   only_conditions = opts[:graph_only_conditions]
2211   conditions = opts[:graph_conditions]
2212   opts[:cartesian_product_number] ||= one_to_one ? 0 : 1
2213   graph_block = opts[:graph_block]
2214   opts[:eager_grapher] ||= proc do |eo|
2215     ds = eo[:self]
2216     ds = ds.graph(opts.apply_eager_graph_limit_strategy(eo[:limit_strategy], eager_graph_dataset(opts, eo)), use_only_conditions ? only_conditions : cks.zip(pkcs) + conditions, eo.merge(:select=>select, :join_type=>eo[:join_type]||join_type, :qualify=>:deep), &graph_block)
2217     # We only load reciprocals for one_to_many associations, as other reciprocals don't make sense
2218     ds.opts[:eager_graph][:reciprocals][eo[:table_alias]] = opts.reciprocal
2219     ds
2220   end
2221       
2222   return if opts[:read_only]
2223 
2224   save_opts = {:validate=>opts[:validate]}
2225   ck_nil_hash ={}
2226   cks.each{|k| ck_nil_hash[k] = nil}
2227 
2228   if one_to_one
2229     opts[:setter] ||= proc do |o|
2230       up_ds = _apply_association_options(opts, opts.associated_dataset.where(cks.zip(cpks.map{|k| get_column_value(k)})))
2231 
2232       if (froms = up_ds.opts[:from]) && (from = froms[0]) && (from.is_a?(Sequel::Dataset) || (from.is_a?(Sequel::SQL::AliasedExpression) && from.expression.is_a?(Sequel::Dataset)))
2233         if old = up_ds.first
2234           cks.each{|k| old.set_column_value(:"#{k}=", nil)}
2235         end
2236         save_old = true
2237       end
2238 
2239       if o
2240         if !o.new? && !save_old
2241           up_ds = up_ds.exclude(o.pk_hash)
2242         end
2243         cks.zip(cpks).each{|k, pk| o.set_column_value(:"#{k}=", get_column_value(pk))}
2244       end
2245 
2246       checked_transaction do
2247         if save_old
2248           old.save(save_opts) || raise(Sequel::Error, "invalid previously associated object, cannot save") if old
2249         else
2250           up_ds.skip_limit_check.update(ck_nil_hash)
2251         end
2252 
2253         o.save(save_opts) || raise(Sequel::Error, "invalid associated object, cannot save") if o
2254       end
2255     end
2256     opts[:_setter] = proc{|o| set_one_to_one_associated_object(opts, o)}
2257   else 
2258     save_opts[:raise_on_failure] = opts[:raise_on_save_failure] != false
2259 
2260     opts[:adder] ||= proc do |o|
2261       cks.zip(cpks).each{|k, pk| o.set_column_value(:"#{k}=", get_column_value(pk))}
2262       o.save(save_opts)
2263     end
2264     
2265     opts[:remover] ||= proc do |o|
2266       cks.each{|k| o.set_column_value(:"#{k}=", nil)}
2267       o.save(save_opts)
2268     end
2269 
2270     opts[:clearer] ||= proc do
2271       _apply_association_options(opts, opts.associated_dataset.where(cks.zip(cpks.map{|k| get_column_value(k)}))).update(ck_nil_hash)
2272     end
2273   end
2274 end
def_one_to_one(opts) click to toggle source

Alias of def_one_to_many, since they share pretty much the same code.

     # File lib/sequel/model/associations.rb
2282 def def_one_to_one(opts)
2283   def_one_to_many(opts)
2284 end
eager_graph_dataset(opts, eager_options) click to toggle source

Return dataset to graph into given the association reflection, applying the :callback option if set.

     # File lib/sequel/model/associations.rb
2287 def eager_graph_dataset(opts, eager_options)
2288   ds = opts.associated_class.dataset
2289   if cb = eager_options[:callback]
2290     ds = cb.call(ds)
2291   end
2292   ds
2293 end
reload_db_schema?() click to toggle source

If not caching associations, reload the database schema by default, ignoring any cached values.

     # File lib/sequel/model/associations.rb
2297 def reload_db_schema?
2298   !@cache_associations
2299 end