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
1566 def all_association_reflections
1567   association_reflections.values
1568 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
1788 def associate(type, name, opts = OPTS, &block)
1789   raise(Error, 'invalid association type') unless assoc_class = Sequel.synchronize{ASSOCIATION_TYPES[type]}
1790   raise(Error, 'Model.associate name argument must be a symbol') unless name.is_a?(Symbol)
1791 
1792   # dup early so we don't modify opts
1793   orig_opts = opts.dup
1794 
1795   if opts[:clone]
1796     cloned_assoc = association_reflection(opts[:clone])
1797     orig_opts = cloned_assoc[:orig_opts].merge(orig_opts)
1798   end
1799 
1800   opts = Hash[default_association_options]
1801   if type_options = default_association_type_options[type]
1802     opts.merge!(type_options)
1803   end
1804   opts.merge!(orig_opts)
1805   opts.merge!(:type => type, :name => name, :cache=>({} if cache_associations), :model => self)
1806 
1807   opts[:block] = block if block
1808   opts[:instance_specific] = true if orig_opts[:dataset]
1809   if !opts.has_key?(:instance_specific) && (block || orig_opts[:block])
1810     # It's possible the association is instance specific, in that it depends on
1811     # values other than the foreign key value.  This needs to be checked for
1812     # in certain places to disable optimizations.
1813     opts[:instance_specific] = _association_instance_specific_default(name)
1814   end
1815   opts = assoc_class.new.merge!(opts)
1816 
1817   if opts[:clone] && !opts.cloneable?(cloned_assoc)
1818     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]})")
1819   end
1820 
1821   opts[:use_placeholder_loader] = !opts[:instance_specific] && !opts[:eager_graph]
1822   opts[:eager_block] = opts[:block] unless opts.include?(:eager_block)
1823   opts[:graph_join_type] ||= :left_outer
1824   opts[:order_eager_graph] = true unless opts.include?(:order_eager_graph)
1825   conds = opts[:conditions]
1826   opts[:graph_alias_base] ||= name
1827   opts[:graph_conditions] = conds if !opts.include?(:graph_conditions) and Sequel.condition_specifier?(conds)
1828   opts[:graph_conditions] = opts.fetch(:graph_conditions, []).to_a
1829   opts[:graph_select] = Array(opts[:graph_select]) if opts[:graph_select]
1830   [:before_add, :before_remove, :after_add, :after_remove, :after_load, :before_set, :after_set].each do |cb_type|
1831     opts[cb_type] = Array(opts[cb_type]) if opts[cb_type]
1832   end
1833 
1834   if opts[:extend]
1835     opts[:extend] = Array(opts[:extend])
1836     opts[:reverse_extend] = opts[:extend].reverse
1837   end
1838 
1839   late_binding_class_option(opts, opts.returns_array? ? singularize(name) : name)
1840   
1841   # Remove :class entry if it exists and is nil, to work with cached_fetch
1842   opts.delete(:class) unless opts[:class]
1843 
1844   send(:"def_#{type}", opts)
1845   def_association_instance_methods(opts)
1846       
1847   orig_opts.delete(:clone)
1848   opts[:orig_class] = orig_opts[:class] || orig_opts[:class_name]
1849   orig_opts.merge!(:class_name=>opts[:class_name], :class=>opts[:class], :block=>opts[:block])
1850   opts[:orig_opts] = orig_opts
1851   # don't add to association_reflections until we are sure there are no errors
1852   association_reflections[name] = opts
1853 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
1856 def association_reflection(name)
1857   association_reflections[name]
1858 end
associations() click to toggle source

Array of association name symbols

     # File lib/sequel/model/associations.rb
1861 def associations
1862   association_reflections.keys
1863 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
1866 def eager_load_results(opts, eo, &block)
1867   opts.eager_load_results(eo, &block)
1868 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
1885 def finalize_associations
1886   @association_reflections.each_value(&:finalize)
1887 end
freeze() click to toggle source

Freeze association related metadata when freezing model class.

Calls superclass method
     # File lib/sequel/model/associations.rb
1871 def freeze
1872   @association_reflections.freeze.each_value(&:freeze)
1873   @autoreloading_associations.freeze.each_value(&:freeze)
1874   @default_association_options.freeze
1875   @default_association_type_options.freeze
1876   @default_association_type_options.each_value(&:freeze)
1877 
1878   super
1879 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
1890 def many_to_many(name, opts=OPTS, &block)
1891   associate(:many_to_many, name, opts, &block)
1892 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
1895 def many_to_one(name, opts=OPTS, &block)
1896   associate(:many_to_one, name, opts, &block)
1897 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
1900 def one_through_one(name, opts=OPTS, &block)
1901   associate(:one_through_one, name, opts, &block)
1902 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
1905 def one_to_many(name, opts=OPTS, &block)
1906   associate(:one_to_many, name, opts, &block)
1907 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
1910 def one_to_one(name, opts=OPTS, &block)
1911   associate(:one_to_one, name, opts, &block)
1912 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
1921 def _association_instance_specific_default(_)
1922   true
1923 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
1927 def association_module(opts=OPTS)
1928   opts.fetch(:methods_module, overridable_methods_module)
1929 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
1934 def association_module_def(name, opts=OPTS, &block)
1935   mod = association_module(opts)
1936   mod.send(:define_method, name, &block)
1937   mod.send(:alias_method, name, name)
1938 end
association_module_delegate_def(name, 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. This method allows passing keywords through the defined methods.

     # File lib/sequel/model/associations.rb
1944 def association_module_delegate_def(name, opts, &block)
1945   mod = association_module(opts)
1946   mod.send(:define_method, name, &block)
1947   # :nocov:
1948   mod.send(:ruby2_keywords, name) if mod.respond_to?(:ruby2_keywords, true)
1949   # :nocov:
1950   mod.send(:alias_method, name, name)
1951 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
1954 def association_module_private_def(name, opts=OPTS, &block)
1955   association_module_def(name, opts, &block)
1956   association_module(opts).send(:private, name)
1957 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
1967 def def_association_instance_methods(opts)
1968   # Always set the method names in the association reflection, even if they
1969   # are not used, for backwards compatibility.
1970   opts[:dataset_method] = :"#{opts[:name]}_dataset"
1971   if opts.returns_array?
1972     sname = singularize(opts[:name])
1973     opts[:_add_method] = :"_add_#{sname}"
1974     opts[:add_method] = :"add_#{sname}"
1975     opts[:_remove_method] = :"_remove_#{sname}"
1976     opts[:remove_method] = :"remove_#{sname}"
1977     opts[:_remove_all_method] = :"_remove_all_#{opts[:name]}"
1978     opts[:remove_all_method] = :"remove_all_#{opts[:name]}"
1979   else
1980     opts[:_setter_method] = :"_#{opts[:name]}="
1981     opts[:setter_method] = :"#{opts[:name]}="
1982   end
1983 
1984   association_module_def(opts.dataset_method, opts){_dataset(opts)}
1985   if opts[:block]
1986     opts[:block_method] = Plugins.def_sequel_method(association_module(opts), "#{opts[:name]}_block", 1, &opts[:block])
1987   end
1988   opts[:dataset_opt_arity] = opts[:dataset].arity == 0 ? 0 : 1
1989   opts[:dataset_opt_method] = Plugins.def_sequel_method(association_module(opts), "#{opts[:name]}_dataset_opt", opts[:dataset_opt_arity], &opts[:dataset])
1990   def_association_method(opts)
1991 
1992   return if opts[:read_only]
1993 
1994   if opts[:setter] && opts[:_setter]
1995     # This is backwards due to backwards compatibility
1996     association_module_private_def(opts[:_setter_method], opts, &opts[:setter])
1997     association_module_def(opts[:setter_method], opts, &opts[:_setter])
1998   end
1999 
2000   if adder = opts[:adder]
2001     association_module_private_def(opts[:_add_method], opts, &adder)
2002     association_module_delegate_def(opts[:add_method], opts){|o,*args| add_associated_object(opts, o, *args)}
2003   end
2004 
2005   if remover = opts[:remover]
2006     association_module_private_def(opts[:_remove_method], opts, &remover)
2007     association_module_delegate_def(opts[:remove_method], opts){|o,*args| remove_associated_object(opts, o, *args)}
2008   end
2009 
2010   if clearer = opts[:clearer]
2011     association_module_private_def(opts[:_remove_all_method], opts, &clearer)
2012     association_module_delegate_def(opts[:remove_all_method], opts){|*args| remove_all_associated_objects(opts, *args)}
2013   end
2014 end
def_association_method(opts) click to toggle source

Adds the association method to the association methods module.

     # File lib/sequel/model/associations.rb
1960 def def_association_method(opts)
1961   association_module_def(opts.association_method, opts) do |dynamic_opts=OPTS, &block|
1962     load_associated_objects(opts, dynamic_opts, &block)
1963   end
1964 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
2017 def def_many_to_many(opts)
2018   one_through_one = opts[:type] == :one_through_one
2019   left = (opts[:left_key] ||= opts.default_left_key)
2020   lcks = opts[:left_keys] = Array(left)
2021   right = (opts[:right_key] ||= opts.default_right_key)
2022   rcks = opts[:right_keys] = Array(right)
2023   left_pk = (opts[:left_primary_key] ||= self.primary_key)
2024   opts[:eager_loader_key] = left_pk unless opts.has_key?(:eager_loader_key)
2025   lcpks = opts[:left_primary_keys] = Array(left_pk)
2026   lpkc = opts[:left_primary_key_column] ||= left_pk
2027   lpkcs = opts[:left_primary_key_columns] ||= Array(lpkc)
2028   raise(Error, "mismatched number of left keys: #{lcks.inspect} vs #{lcpks.inspect}") unless lcks.length == lcpks.length
2029   if opts[:right_primary_key]
2030     rcpks = Array(opts[:right_primary_key])
2031     raise(Error, "mismatched number of right keys: #{rcks.inspect} vs #{rcpks.inspect}") unless rcks.length == rcpks.length
2032   end
2033   opts[:uses_left_composite_keys] = lcks.length > 1
2034   opts[:uses_right_composite_keys] = rcks.length > 1
2035   opts[:cartesian_product_number] ||= one_through_one ? 0 : 1
2036   join_table = (opts[:join_table] ||= opts.default_join_table)
2037   opts[:left_key_alias] ||= opts.default_associated_key_alias
2038   opts[:graph_join_table_join_type] ||= opts[:graph_join_type]
2039   if opts[:uniq]
2040     opts[:after_load] ||= []
2041     opts[:after_load].unshift(:array_uniq!)
2042   end
2043   opts[:dataset] ||= opts.association_dataset_proc
2044   opts[:eager_loader] ||= opts.method(:default_eager_loader)
2045   
2046   join_type = opts[:graph_join_type]
2047   select = opts[:graph_select]
2048   use_only_conditions = opts.include?(:graph_only_conditions)
2049   only_conditions = opts[:graph_only_conditions]
2050   conditions = opts[:graph_conditions]
2051   graph_block = opts[:graph_block]
2052   graph_jt_conds = opts[:graph_join_table_conditions] = opts.fetch(:graph_join_table_conditions, []).to_a
2053   use_jt_only_conditions = opts.include?(:graph_join_table_only_conditions)
2054   jt_only_conditions = opts[:graph_join_table_only_conditions]
2055   jt_join_type = opts[:graph_join_table_join_type]
2056   jt_graph_block = opts[:graph_join_table_block]
2057   opts[:eager_grapher] ||= proc do |eo|
2058     ds = eo[:self]
2059     egls = eo[:limit_strategy]
2060     if egls && egls != :ruby
2061       associated_key_array = opts.associated_key_array
2062       orig_egds = egds = eager_graph_dataset(opts, eo)
2063       egds = egds.
2064         inner_join(join_table, rcks.zip(opts.right_primary_keys) + graph_jt_conds, :qualify=>:deep).
2065         select_all(egds.first_source).
2066         select_append(*associated_key_array)
2067       egds = opts.apply_eager_graph_limit_strategy(egls, egds)
2068       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)
2069     else
2070       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)
2071       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)
2072     end
2073   end
2074       
2075   return if opts[:read_only]
2076       
2077   if one_through_one
2078     opts[:setter] ||= proc do |o|
2079       h = {}
2080       lh = lcks.zip(lcpks.map{|k| get_column_value(k)})
2081       jtds = _join_table_dataset(opts).where(lh)
2082 
2083       checked_transaction do
2084         current = jtds.first
2085 
2086         if o
2087           new_values = []
2088           rcks.zip(opts.right_primary_key_methods).each{|k, pk| new_values << (h[k] = o.get_column_value(pk))}
2089         end
2090 
2091         if current
2092           current_values = rcks.map{|k| current[k]}
2093           jtds = jtds.where(rcks.zip(current_values))
2094           if o
2095             if current_values != new_values
2096               jtds.update(h)
2097             end
2098           else
2099             jtds.delete
2100           end
2101         elsif o
2102           lh.each{|k,v| h[k] = v}
2103           jtds.insert(h)
2104         end
2105       end
2106     end
2107     opts[:_setter] = proc{|o| set_one_through_one_associated_object(opts, o)}
2108   else 
2109     opts[:adder] ||= proc do |o|
2110       h = {}
2111       lcks.zip(lcpks).each{|k, pk| h[k] = get_column_value(pk)}
2112       rcks.zip(opts.right_primary_key_methods).each{|k, pk| h[k] = o.get_column_value(pk)}
2113       _join_table_dataset(opts).insert(h)
2114     end
2115 
2116     opts[:remover] ||= proc do |o|
2117       _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
2118     end
2119 
2120     opts[:clearer] ||= proc do
2121       _join_table_dataset(opts).where(lcks.zip(lcpks.map{|k| get_column_value(k)})).delete
2122     end
2123   end
2124 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
2127 def def_many_to_one(opts)
2128   name = opts[:name]
2129   opts[:key] = opts.default_key unless opts.has_key?(:key)
2130   key = opts[:key]
2131   opts[:eager_loader_key] = key unless opts.has_key?(:eager_loader_key)
2132   cks = opts[:graph_keys] = opts[:keys] = Array(key)
2133   opts[:key_column] ||= key
2134   opts[:graph_keys] = opts[:key_columns] = Array(opts[:key_column])
2135   opts[:qualified_key] = opts.qualify_cur(key)
2136   if opts[:primary_key]
2137     cpks = Array(opts[:primary_key])
2138     raise(Error, "mismatched number of keys: #{cks.inspect} vs #{cpks.inspect}") unless cks.length == cpks.length
2139   end
2140   uses_cks = opts[:uses_composite_keys] = cks.length > 1
2141   opts[:cartesian_product_number] ||= 0
2142 
2143   if !opts.has_key?(:many_to_one_pk_lookup) &&
2144      (opts[:dataset] || opts[:conditions] || opts[:block] || opts[:select] ||
2145       (opts.has_key?(:key) && opts[:key] == nil))
2146     opts[:many_to_one_pk_lookup] = false
2147   end
2148   auto_assocs = @autoreloading_associations
2149   cks.each do |k|
2150     (auto_assocs[k] ||= []) << name
2151   end
2152 
2153   opts[:dataset] ||= opts.association_dataset_proc
2154   opts[:eager_loader] ||= proc do |eo|
2155     h = eo[:id_map]
2156     pk_meths = opts.primary_key_methods
2157 
2158     eager_load_results(opts, eo) do |assoc_record|
2159       hash_key = uses_cks ? pk_meths.map{|k| assoc_record.get_column_value(k)} : assoc_record.get_column_value(opts.primary_key_method)
2160       h[hash_key].each{|object| object.associations[name] = assoc_record}
2161     end
2162   end
2163       
2164   join_type = opts[:graph_join_type]
2165   select = opts[:graph_select]
2166   use_only_conditions = opts.include?(:graph_only_conditions)
2167   only_conditions = opts[:graph_only_conditions]
2168   conditions = opts[:graph_conditions]
2169   graph_block = opts[:graph_block]
2170   graph_cks = opts[:graph_keys]
2171   opts[:eager_grapher] ||= proc do |eo|
2172     ds = eo[:self]
2173     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)
2174   end
2175       
2176   return if opts[:read_only]
2177       
2178   opts[:setter] ||= proc{|o| cks.zip(opts.primary_key_methods).each{|k, pk| set_column_value(:"#{k}=", (o.get_column_value(pk) if o))}}
2179   opts[:_setter] = proc{|o| set_associated_object(opts, o)}
2180 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
2294 def def_one_through_one(opts)
2295   def_many_to_many(opts)
2296 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
2183 def def_one_to_many(opts)
2184   one_to_one = opts[:type] == :one_to_one
2185   name = opts[:name]
2186   key = (opts[:key] ||= opts.default_key)
2187   km = opts[:key_method] ||= opts[:key]
2188   cks = opts[:keys] = Array(key)
2189   opts[:key_methods] = Array(opts[:key_method])
2190   primary_key = (opts[:primary_key] ||= self.primary_key)
2191   opts[:eager_loader_key] = primary_key unless opts.has_key?(:eager_loader_key)
2192   cpks = opts[:primary_keys] = Array(primary_key)
2193   pkc = opts[:primary_key_column] ||= primary_key
2194   pkcs = opts[:primary_key_columns] ||= Array(pkc)
2195   raise(Error, "mismatched number of keys: #{cks.inspect} vs #{cpks.inspect}") unless cks.length == cpks.length
2196   uses_cks = opts[:uses_composite_keys] = cks.length > 1
2197   opts[:dataset] ||= opts.association_dataset_proc
2198   opts[:eager_loader] ||= proc do |eo|
2199     h = eo[:id_map]
2200     reciprocal = opts.reciprocal
2201     assign_singular = opts.assign_singular?
2202     delete_rn = opts.delete_row_number_column
2203 
2204     eager_load_results(opts, eo) do |assoc_record|
2205       assoc_record.values.delete(delete_rn) if delete_rn
2206       hash_key = uses_cks ? km.map{|k| assoc_record.get_column_value(k)} : assoc_record.get_column_value(km)
2207       objects = h[hash_key]
2208       if assign_singular
2209         objects.each do |object| 
2210           unless object.associations[name]
2211             object.associations[name] = assoc_record
2212             assoc_record.associations[reciprocal] = object if reciprocal
2213           end
2214         end
2215       else
2216         objects.each do |object| 
2217           object.associations[name].push(assoc_record)
2218           assoc_record.associations[reciprocal] = object if reciprocal
2219         end
2220       end
2221     end
2222   end
2223   
2224   join_type = opts[:graph_join_type]
2225   select = opts[:graph_select]
2226   use_only_conditions = opts.include?(:graph_only_conditions)
2227   only_conditions = opts[:graph_only_conditions]
2228   conditions = opts[:graph_conditions]
2229   opts[:cartesian_product_number] ||= one_to_one ? 0 : 1
2230   graph_block = opts[:graph_block]
2231   opts[:eager_grapher] ||= proc do |eo|
2232     ds = eo[:self]
2233     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)
2234     # We only load reciprocals for one_to_many associations, as other reciprocals don't make sense
2235     ds.opts[:eager_graph][:reciprocals][eo[:table_alias]] = opts.reciprocal
2236     ds
2237   end
2238       
2239   return if opts[:read_only]
2240 
2241   save_opts = {:validate=>opts[:validate]}
2242   ck_nil_hash ={}
2243   cks.each{|k| ck_nil_hash[k] = nil}
2244 
2245   if one_to_one
2246     opts[:setter] ||= proc do |o|
2247       up_ds = _apply_association_options(opts, opts.associated_dataset.where(cks.zip(cpks.map{|k| get_column_value(k)})))
2248 
2249       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)))
2250         if old = up_ds.first
2251           cks.each{|k| old.set_column_value(:"#{k}=", nil)}
2252         end
2253         save_old = true
2254       end
2255 
2256       if o
2257         if !o.new? && !save_old
2258           up_ds = up_ds.exclude(o.pk_hash)
2259         end
2260         cks.zip(cpks).each{|k, pk| o.set_column_value(:"#{k}=", get_column_value(pk))}
2261       end
2262 
2263       checked_transaction do
2264         if save_old
2265           old.save(save_opts) || raise(Sequel::Error, "invalid previously associated object, cannot save") if old
2266         else
2267           up_ds.skip_limit_check.update(ck_nil_hash)
2268         end
2269 
2270         o.save(save_opts) || raise(Sequel::Error, "invalid associated object, cannot save") if o
2271       end
2272     end
2273     opts[:_setter] = proc{|o| set_one_to_one_associated_object(opts, o)}
2274   else 
2275     save_opts[:raise_on_failure] = opts[:raise_on_save_failure] != false
2276 
2277     opts[:adder] ||= proc do |o|
2278       cks.zip(cpks).each{|k, pk| o.set_column_value(:"#{k}=", get_column_value(pk))}
2279       o.save(save_opts)
2280     end
2281     
2282     opts[:remover] ||= proc do |o|
2283       cks.each{|k| o.set_column_value(:"#{k}=", nil)}
2284       o.save(save_opts)
2285     end
2286 
2287     opts[:clearer] ||= proc do
2288       _apply_association_options(opts, opts.associated_dataset.where(cks.zip(cpks.map{|k| get_column_value(k)}))).update(ck_nil_hash)
2289     end
2290   end
2291 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
2299 def def_one_to_one(opts)
2300   def_one_to_many(opts)
2301 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
2304 def eager_graph_dataset(opts, eager_options)
2305   ds = opts.associated_class.dataset
2306   if cb = eager_options[:callback]
2307     ds = cb.call(ds)
2308   end
2309   ds
2310 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
2314 def reload_db_schema?
2315   !@cache_associations
2316 end