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
1600 def all_association_reflections
1601   association_reflections.values
1602 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). Set to nil to not define a add_* method for the association.

: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

:allow_eager_graph

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

:allow_filtering_by

If set to false, you cannot use the association when filtering

: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). Set to nil to not define a remove_all_* method for the association.

: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

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.

:instance_specific

Marks the association as instance specific. Should be used if the association block uses instance specific state, or transient state (accessing current date/time, etc.).

: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.

:no_association_method

Do not add a method for the association. This can save memory if the association method is never used.

:no_dataset_method

Do not add a method for the association dataset. This can save memory if the dataset method is never used.

: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). Set to nil to not define a remove_* method for the association.

: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). Set to nil to not define a setter method for the association.

: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.

:join_table_db

When retrieving records when using lazy loading or eager loading via eager, instead of a join between to the join table and the associated table, use a separate query for the join table using the given Database object.

: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
1837 def associate(type, name, opts = OPTS, &block)
1838   raise(Error, 'invalid association type') unless assoc_class = Sequel.synchronize{ASSOCIATION_TYPES[type]}
1839   raise(Error, 'Model.associate name argument must be a symbol') unless name.is_a?(Symbol)
1840 
1841   # dup early so we don't modify opts
1842   orig_opts = opts.dup
1843 
1844   if opts[:clone]
1845     cloned_assoc = association_reflection(opts[:clone])
1846     remove_class_name = orig_opts[:class] && !orig_opts[:class_name]
1847     orig_opts = cloned_assoc[:orig_opts].merge(orig_opts)
1848     orig_opts.delete(:class_name) if remove_class_name
1849   end
1850 
1851   opts = Hash[default_association_options]
1852   if type_options = default_association_type_options[type]
1853     opts.merge!(type_options)
1854   end
1855   opts.merge!(orig_opts)
1856   opts.merge!(:type => type, :name => name, :cache=>({} if cache_associations), :model => self)
1857 
1858   opts[:block] = block if block
1859   opts[:instance_specific] = true if orig_opts[:dataset]
1860   if !opts.has_key?(:instance_specific) && (block || orig_opts[:block])
1861     # It's possible the association is instance specific, in that it depends on
1862     # values other than the foreign key value.  This needs to be checked for
1863     # in certain places to disable optimizations.
1864     opts[:instance_specific] = _association_instance_specific_default(name)
1865   end
1866   if (orig_opts[:instance_specific] || orig_opts[:dataset]) && !opts.has_key?(:allow_eager) && !opts[:eager_loader]
1867     # For associations explicitly marked as instance specific, or that use the
1868     # :dataset option, where :allow_eager is not set, and no :eager_loader is
1869     # provided, disallow eager loading.  In these cases, eager loading is
1870     # unlikely to work.  This is not done for implicit setting of :instance_specific,
1871     # because implicit use is done by default for all associations with blocks,
1872     # and the vast majority of associations with blocks use the block for filtering
1873     # in a manner compatible with eager loading.
1874     opts[:allow_eager] = false
1875   end
1876   opts = assoc_class.new.merge!(opts)
1877 
1878   if opts[:clone] && !opts.cloneable?(cloned_assoc)
1879     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]})")
1880   end
1881 
1882   opts[:use_placeholder_loader] = !opts[:instance_specific] && !opts[:eager_graph]
1883   opts[:eager_block] = opts[:block] unless opts.include?(:eager_block)
1884   opts[:graph_join_type] ||= :left_outer
1885   opts[:order_eager_graph] = true unless opts.include?(:order_eager_graph)
1886   conds = opts[:conditions]
1887   opts[:graph_alias_base] ||= name
1888   opts[:graph_conditions] = conds if !opts.include?(:graph_conditions) and Sequel.condition_specifier?(conds)
1889   opts[:graph_conditions] = opts.fetch(:graph_conditions, []).to_a
1890   opts[:graph_select] = Array(opts[:graph_select]) if opts[:graph_select]
1891   [:before_add, :before_remove, :after_add, :after_remove, :after_load, :before_set, :after_set].each do |cb_type|
1892     opts[cb_type] = Array(opts[cb_type]) if opts[cb_type]
1893   end
1894 
1895   if opts[:extend]
1896     opts[:extend] = Array(opts[:extend])
1897     opts[:reverse_extend] = opts[:extend].reverse
1898   end
1899 
1900   late_binding_class_option(opts, opts.returns_array? ? singularize(name) : name)
1901   
1902   # Remove :class entry if it exists and is nil, to work with cached_fetch
1903   opts.delete(:class) unless opts[:class]
1904 
1905   def_association(opts)
1906       
1907   orig_opts.delete(:clone)
1908   opts[:orig_class] = orig_opts[:class] || orig_opts[:class_name]
1909   orig_opts.merge!(:class_name=>opts[:class_name], :class=>opts[:class], :block=>opts[:block])
1910   opts[:orig_opts] = orig_opts
1911   # don't add to association_reflections until we are sure there are no errors
1912   association_reflections[name] = opts
1913 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
1916 def association_reflection(name)
1917   association_reflections[name]
1918 end
associations() click to toggle source

Array of association name symbols

     # File lib/sequel/model/associations.rb
1921 def associations
1922   association_reflections.keys
1923 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
1926 def eager_load_results(opts, eo, &block)
1927   opts.eager_load_results(eo, &block)
1928 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
1945 def finalize_associations
1946   @association_reflections.each_value(&:finalize)
1947 end
freeze() click to toggle source

Freeze association related metadata when freezing model class.

Calls superclass method
     # File lib/sequel/model/associations.rb
1931 def freeze
1932   @association_reflections.freeze.each_value(&:freeze)
1933   @autoreloading_associations.freeze.each_value(&:freeze)
1934   @default_association_options.freeze
1935   @default_association_type_options.freeze
1936   @default_association_type_options.each_value(&:freeze)
1937 
1938   super
1939 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
1950 def many_to_many(name, opts=OPTS, &block)
1951   associate(:many_to_many, name, opts, &block)
1952 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
1955 def many_to_one(name, opts=OPTS, &block)
1956   associate(:many_to_one, name, opts, &block)
1957 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
1960 def one_through_one(name, opts=OPTS, &block)
1961   associate(:one_through_one, name, opts, &block)
1962 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
1965 def one_to_many(name, opts=OPTS, &block)
1966   associate(:one_to_many, name, opts, &block)
1967 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
1970 def one_to_one(name, opts=OPTS, &block)
1971   associate(:one_to_one, name, opts, &block)
1972 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
1981 def _association_instance_specific_default(_)
1982   true
1983 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
1987 def association_module(opts=OPTS)
1988   opts.fetch(:methods_module, overridable_methods_module)
1989 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
1994 def association_module_def(name, opts=OPTS, &block)
1995   mod = association_module(opts)
1996   mod.send(:define_method, name, &block)
1997   mod.send(:alias_method, name, name)
1998 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
2004 def association_module_delegate_def(name, opts, &block)
2005   mod = association_module(opts)
2006   mod.send(:define_method, name, &block)
2007   # :nocov:
2008   mod.send(:ruby2_keywords, name) if mod.respond_to?(:ruby2_keywords, true)
2009   # :nocov:
2010   mod.send(:alias_method, name, name)
2011 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
2014 def association_module_private_def(name, opts=OPTS, &block)
2015   association_module_def(name, opts, &block)
2016   association_module(opts).send(:private, name)
2017 end
def_association(opts) click to toggle source

Delegate to the type-specific association method to setup the association, and define the association instance methods.

     # File lib/sequel/model/associations.rb
2021 def def_association(opts)
2022   send(:"def_#{opts[:type]}", opts)
2023   def_association_instance_methods(opts)
2024 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
2034 def def_association_instance_methods(opts)
2035   # Always set the method names in the association reflection, even if they
2036   # are not used, for backwards compatibility.
2037   opts[:dataset_method] = :"#{opts[:name]}_dataset"
2038   if opts.returns_array?
2039     sname = singularize(opts[:name])
2040     opts[:_add_method] = :"_add_#{sname}"
2041     opts[:add_method] = :"add_#{sname}"
2042     opts[:_remove_method] = :"_remove_#{sname}"
2043     opts[:remove_method] = :"remove_#{sname}"
2044     opts[:_remove_all_method] = :"_remove_all_#{opts[:name]}"
2045     opts[:remove_all_method] = :"remove_all_#{opts[:name]}"
2046   else
2047     opts[:_setter_method] = :"_#{opts[:name]}="
2048     opts[:setter_method] = :"#{opts[:name]}="
2049   end
2050 
2051   association_module_def(opts.dataset_method, opts){_dataset(opts)} unless opts[:no_dataset_method]
2052   if opts[:block]
2053     opts[:block_method] = Plugins.def_sequel_method(association_module(opts), "#{opts[:name]}_block", 1, &opts[:block])
2054   end
2055   opts[:dataset_opt_arity] = opts[:dataset].arity == 0 ? 0 : 1
2056   opts[:dataset_opt_method] = Plugins.def_sequel_method(association_module(opts), "#{opts[:name]}_dataset_opt", opts[:dataset_opt_arity], &opts[:dataset])
2057   def_association_method(opts) unless opts[:no_association_method]
2058 
2059   return if opts[:read_only]
2060 
2061   if opts[:setter] && opts[:_setter]
2062     # This is backwards due to backwards compatibility
2063     association_module_private_def(opts[:_setter_method], opts, &opts[:setter])
2064     association_module_def(opts[:setter_method], opts, &opts[:_setter])
2065   end
2066 
2067   if adder = opts[:adder]
2068     association_module_private_def(opts[:_add_method], opts, &adder)
2069     association_module_delegate_def(opts[:add_method], opts){|o,*args| add_associated_object(opts, o, *args)}
2070   end
2071 
2072   if remover = opts[:remover]
2073     association_module_private_def(opts[:_remove_method], opts, &remover)
2074     association_module_delegate_def(opts[:remove_method], opts){|o,*args| remove_associated_object(opts, o, *args)}
2075   end
2076 
2077   if clearer = opts[:clearer]
2078     association_module_private_def(opts[:_remove_all_method], opts, &clearer)
2079     association_module_delegate_def(opts[:remove_all_method], opts){|*args| remove_all_associated_objects(opts, *args)}
2080   end
2081 end
def_association_method(opts) click to toggle source

Adds the association method to the association methods module.

     # File lib/sequel/model/associations.rb
2027 def def_association_method(opts)
2028   association_module_def(opts.association_method, opts) do |dynamic_opts=OPTS, &block|
2029     load_associated_objects(opts, dynamic_opts, &block)
2030   end
2031 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
2084 def def_many_to_many(opts)
2085   one_through_one = opts[:type] == :one_through_one
2086   left = (opts[:left_key] ||= opts.default_left_key)
2087   lcks = opts[:left_keys] = Array(left)
2088   right = (opts[:right_key] ||= opts.default_right_key)
2089   rcks = opts[:right_keys] = Array(right)
2090   left_pk = (opts[:left_primary_key] ||= self.primary_key)
2091   opts[:eager_loader_key] = left_pk unless opts.has_key?(:eager_loader_key)
2092   lcpks = opts[:left_primary_keys] = Array(left_pk)
2093   lpkc = opts[:left_primary_key_column] ||= left_pk
2094   lpkcs = opts[:left_primary_key_columns] ||= Array(lpkc)
2095   raise(Error, "mismatched number of left keys: #{lcks.inspect} vs #{lcpks.inspect}") unless lcks.length == lcpks.length
2096   if opts[:right_primary_key]
2097     rcpks = Array(opts[:right_primary_key])
2098     raise(Error, "mismatched number of right keys: #{rcks.inspect} vs #{rcpks.inspect}") unless rcks.length == rcpks.length
2099   end
2100   opts[:uses_left_composite_keys] = lcks.length > 1
2101   uses_rcks = opts[:uses_right_composite_keys] = rcks.length > 1
2102   opts[:cartesian_product_number] ||= one_through_one ? 0 : 1
2103   join_table = (opts[:join_table] ||= opts.default_join_table)
2104   opts[:left_key_alias] ||= opts.default_associated_key_alias
2105   opts[:graph_join_table_join_type] ||= opts[:graph_join_type]
2106   if opts[:uniq]
2107     opts[:after_load] ||= []
2108     opts[:after_load].unshift(:array_uniq!)
2109   end
2110   if join_table_db = opts[:join_table_db]
2111     opts[:use_placeholder_loader] = false
2112     opts[:allow_eager_graph] = false
2113     opts[:allow_filtering_by] = false
2114     opts[:eager_limit_strategy] = nil
2115     join_table_ds = join_table_db.from(join_table)
2116     opts[:dataset] ||= proc do |r|
2117       vals = join_table_ds.where(lcks.zip(lcpks.map{|k| get_column_value(k)})).select_map(right)
2118       ds = r.associated_dataset.where(opts.right_primary_key => vals)
2119       if uses_rcks
2120         vals.delete_if{|v| v.any?(&:nil?)}
2121       else
2122         vals.delete(nil)
2123       end
2124       ds = ds.clone(:no_results=>true) if vals.empty?
2125       ds
2126     end
2127     opts[:eager_loader] ||= proc do |eo|
2128       h = eo[:id_map]
2129       assign_singular = opts.assign_singular?
2130       rpk = opts.right_primary_key
2131       name = opts[:name]
2132 
2133       join_map = join_table_ds.where(left=>h.keys).select_hash_groups(right, left)
2134 
2135       if uses_rcks
2136         join_map.delete_if{|v,| v.any?(&:nil?)}
2137       else
2138         join_map.delete(nil)
2139       end
2140 
2141       eo = Hash[eo]
2142 
2143       if join_map.empty?
2144         eo[:no_results] = true
2145       else
2146         join_map.each_value do |vs|
2147           vs.replace(vs.flat_map{|v| h[v]})
2148           vs.uniq!
2149         end
2150 
2151         eo[:loader] = false
2152         eo[:right_keys] = join_map.keys
2153       end
2154 
2155       opts[:model].eager_load_results(opts, eo) do |assoc_record|
2156         rpkv = if uses_rcks
2157           assoc_record.values.values_at(*rpk)
2158         else
2159           assoc_record.values[rpk]
2160         end
2161 
2162         objects = join_map[rpkv]
2163 
2164         if assign_singular
2165           objects.each do |object|
2166             object.associations[name] ||= assoc_record
2167           end
2168         else
2169           objects.each do |object|
2170             object.associations[name].push(assoc_record)
2171           end
2172         end
2173       end
2174     end
2175   else
2176     opts[:dataset] ||= opts.association_dataset_proc
2177     opts[:eager_loader] ||= opts.method(:default_eager_loader)
2178   end
2179   
2180   join_type = opts[:graph_join_type]
2181   select = opts[:graph_select]
2182   use_only_conditions = opts.include?(:graph_only_conditions)
2183   only_conditions = opts[:graph_only_conditions]
2184   conditions = opts[:graph_conditions]
2185   graph_block = opts[:graph_block]
2186   graph_jt_conds = opts[:graph_join_table_conditions] = opts.fetch(:graph_join_table_conditions, []).to_a
2187   use_jt_only_conditions = opts.include?(:graph_join_table_only_conditions)
2188   jt_only_conditions = opts[:graph_join_table_only_conditions]
2189   jt_join_type = opts[:graph_join_table_join_type]
2190   jt_graph_block = opts[:graph_join_table_block]
2191   opts[:eager_grapher] ||= proc do |eo|
2192     ds = eo[:self]
2193     egls = eo[:limit_strategy]
2194     if egls && egls != :ruby
2195       associated_key_array = opts.associated_key_array
2196       orig_egds = egds = eager_graph_dataset(opts, eo)
2197       egds = egds.
2198         inner_join(join_table, rcks.zip(opts.right_primary_keys) + graph_jt_conds, :qualify=>:deep).
2199         select_all(egds.first_source).
2200         select_append(*associated_key_array)
2201       egds = opts.apply_eager_graph_limit_strategy(egls, egds)
2202       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)
2203     else
2204       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)
2205       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)
2206     end
2207   end
2208       
2209   return if opts[:read_only]
2210       
2211   if one_through_one
2212     unless opts.has_key?(:setter)
2213       opts[:setter] = proc do |o|
2214         h = {}
2215         lh = lcks.zip(lcpks.map{|k| get_column_value(k)})
2216         jtds = _join_table_dataset(opts).where(lh)
2217 
2218         checked_transaction do
2219           current = jtds.first
2220 
2221           if o
2222             new_values = []
2223             rcks.zip(opts.right_primary_key_methods).each{|k, pk| new_values << (h[k] = o.get_column_value(pk))}
2224           end
2225 
2226           if current
2227             current_values = rcks.map{|k| current[k]}
2228             jtds = jtds.where(rcks.zip(current_values))
2229             if o
2230               if current_values != new_values
2231                 jtds.update(h)
2232               end
2233             else
2234               jtds.delete
2235             end
2236           elsif o
2237             lh.each{|k,v| h[k] = v}
2238             jtds.insert(h)
2239           end
2240         end
2241       end
2242     end
2243     if opts.fetch(:setter, true)
2244       opts[:_setter] = proc{|o| set_one_through_one_associated_object(opts, o)}
2245     end
2246   else 
2247     unless opts.has_key?(:adder)
2248       opts[:adder] = proc do |o|
2249         h = {}
2250         lcks.zip(lcpks).each{|k, pk| h[k] = get_column_value(pk)}
2251         rcks.zip(opts.right_primary_key_methods).each{|k, pk| h[k] = o.get_column_value(pk)}
2252         _join_table_dataset(opts).insert(h)
2253       end
2254     end
2255 
2256     unless opts.has_key?(:remover)
2257       opts[:remover] = proc do |o|
2258         _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
2259       end
2260     end
2261 
2262     unless opts.has_key?(:clearer)
2263       opts[:clearer] = proc do
2264         _join_table_dataset(opts).where(lcks.zip(lcpks.map{|k| get_column_value(k)})).delete
2265       end
2266     end
2267   end
2268 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
2271 def def_many_to_one(opts)
2272   name = opts[:name]
2273   opts[:key] = opts.default_key unless opts.has_key?(:key)
2274   key = opts[:key]
2275   opts[:eager_loader_key] = key unless opts.has_key?(:eager_loader_key)
2276   cks = opts[:graph_keys] = opts[:keys] = Array(key)
2277   opts[:key_column] ||= key
2278   opts[:graph_keys] = opts[:key_columns] = Array(opts[:key_column])
2279   opts[:qualified_key] = opts.qualify_cur(key)
2280   if opts[:primary_key]
2281     cpks = Array(opts[:primary_key])
2282     raise(Error, "mismatched number of keys: #{cks.inspect} vs #{cpks.inspect}") unless cks.length == cpks.length
2283   end
2284   uses_cks = opts[:uses_composite_keys] = cks.length > 1
2285   opts[:cartesian_product_number] ||= 0
2286 
2287   if !opts.has_key?(:many_to_one_pk_lookup) &&
2288      (opts[:dataset] || opts[:conditions] || opts[:block] || opts[:select] ||
2289       (opts.has_key?(:key) && opts[:key] == nil))
2290     opts[:many_to_one_pk_lookup] = false
2291   end
2292   auto_assocs = @autoreloading_associations
2293   cks.each do |k|
2294     (auto_assocs[k] ||= []) << name
2295   end
2296 
2297   opts[:dataset] ||= opts.association_dataset_proc
2298   opts[:eager_loader] ||= proc do |eo|
2299     h = eo[:id_map]
2300     pk_meths = opts.primary_key_methods
2301 
2302     eager_load_results(opts, eo) do |assoc_record|
2303       hash_key = uses_cks ? pk_meths.map{|k| assoc_record.get_column_value(k)} : assoc_record.get_column_value(opts.primary_key_method)
2304       h[hash_key].each{|object| object.associations[name] = assoc_record}
2305     end
2306   end
2307       
2308   join_type = opts[:graph_join_type]
2309   select = opts[:graph_select]
2310   use_only_conditions = opts.include?(:graph_only_conditions)
2311   only_conditions = opts[:graph_only_conditions]
2312   conditions = opts[:graph_conditions]
2313   graph_block = opts[:graph_block]
2314   graph_cks = opts[:graph_keys]
2315   opts[:eager_grapher] ||= proc do |eo|
2316     ds = eo[:self]
2317     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)
2318   end
2319       
2320   return if opts[:read_only]
2321       
2322   unless opts.has_key?(:setter)
2323     opts[:setter] = proc{|o| cks.zip(opts.primary_key_methods).each{|k, pk| set_column_value(:"#{k}=", (o.get_column_value(pk) if o))}}
2324   end
2325   if opts.fetch(:setter, true)
2326     opts[:_setter] = proc{|o| set_associated_object(opts, o)}
2327   end
2328 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
2452 def def_one_through_one(opts)
2453   def_many_to_many(opts)
2454 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
2331 def def_one_to_many(opts)
2332   one_to_one = opts[:type] == :one_to_one
2333   name = opts[:name]
2334   key = (opts[:key] ||= opts.default_key)
2335   km = opts[:key_method] ||= opts[:key]
2336   cks = opts[:keys] = Array(key)
2337   opts[:key_methods] = Array(opts[:key_method])
2338   primary_key = (opts[:primary_key] ||= self.primary_key)
2339   opts[:eager_loader_key] = primary_key unless opts.has_key?(:eager_loader_key)
2340   cpks = opts[:primary_keys] = Array(primary_key)
2341   pkc = opts[:primary_key_column] ||= primary_key
2342   pkcs = opts[:primary_key_columns] ||= Array(pkc)
2343   raise(Error, "mismatched number of keys: #{cks.inspect} vs #{cpks.inspect}") unless cks.length == cpks.length
2344   uses_cks = opts[:uses_composite_keys] = cks.length > 1
2345   opts[:dataset] ||= opts.association_dataset_proc
2346   opts[:eager_loader] ||= proc do |eo|
2347     h = eo[:id_map]
2348     reciprocal = opts.reciprocal
2349     assign_singular = opts.assign_singular?
2350     delete_rn = opts.delete_row_number_column
2351 
2352     eager_load_results(opts, eo) do |assoc_record|
2353       assoc_record.values.delete(delete_rn) if delete_rn
2354       hash_key = uses_cks ? km.map{|k| assoc_record.get_column_value(k)} : assoc_record.get_column_value(km)
2355       objects = h[hash_key]
2356       if assign_singular
2357         objects.each do |object| 
2358           unless object.associations[name]
2359             object.associations[name] = assoc_record
2360             assoc_record.associations[reciprocal] = object if reciprocal
2361           end
2362         end
2363       else
2364         objects.each do |object| 
2365           object.associations[name].push(assoc_record)
2366           assoc_record.associations[reciprocal] = object if reciprocal
2367         end
2368       end
2369     end
2370   end
2371   
2372   join_type = opts[:graph_join_type]
2373   select = opts[:graph_select]
2374   use_only_conditions = opts.include?(:graph_only_conditions)
2375   only_conditions = opts[:graph_only_conditions]
2376   conditions = opts[:graph_conditions]
2377   opts[:cartesian_product_number] ||= one_to_one ? 0 : 1
2378   graph_block = opts[:graph_block]
2379   opts[:eager_grapher] ||= proc do |eo|
2380     ds = eo[:self]
2381     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)
2382     # We only load reciprocals for one_to_many associations, as other reciprocals don't make sense
2383     ds.opts[:eager_graph][:reciprocals][eo[:table_alias]] = opts.reciprocal
2384     ds
2385   end
2386       
2387   return if opts[:read_only]
2388 
2389   save_opts = {:validate=>opts[:validate]}
2390   ck_nil_hash ={}
2391   cks.each{|k| ck_nil_hash[k] = nil}
2392 
2393   if one_to_one
2394     unless opts.has_key?(:setter)
2395       opts[:setter] = proc do |o|
2396         up_ds = _apply_association_options(opts, opts.associated_dataset.where(cks.zip(cpks.map{|k| get_column_value(k)})))
2397 
2398         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)))
2399           if old = up_ds.first
2400             cks.each{|k| old.set_column_value(:"#{k}=", nil)}
2401           end
2402           save_old = true
2403         end
2404 
2405         if o
2406           if !o.new? && !save_old
2407             up_ds = up_ds.exclude(o.pk_hash)
2408           end
2409           cks.zip(cpks).each{|k, pk| o.set_column_value(:"#{k}=", get_column_value(pk))}
2410         end
2411 
2412         checked_transaction do
2413           if save_old
2414             old.save(save_opts) || raise(Sequel::Error, "invalid previously associated object, cannot save") if old
2415           else
2416             up_ds.skip_limit_check.update(ck_nil_hash)
2417           end
2418 
2419           o.save(save_opts) || raise(Sequel::Error, "invalid associated object, cannot save") if o
2420         end
2421       end
2422     end
2423     if opts.fetch(:setter, true)
2424       opts[:_setter] = proc{|o| set_one_to_one_associated_object(opts, o)}
2425     end
2426   else 
2427     save_opts[:raise_on_failure] = opts[:raise_on_save_failure] != false
2428 
2429     unless opts.has_key?(:adder)
2430       opts[:adder] = proc do |o|
2431         cks.zip(cpks).each{|k, pk| o.set_column_value(:"#{k}=", get_column_value(pk))}
2432         o.save(save_opts)
2433       end
2434     end
2435     
2436     unless opts.has_key?(:remover)
2437       opts[:remover] = proc do |o|
2438         cks.each{|k| o.set_column_value(:"#{k}=", nil)}
2439         o.save(save_opts)
2440       end
2441     end
2442 
2443     unless opts.has_key?(:clearer)
2444       opts[:clearer] = proc do
2445         _apply_association_options(opts, opts.associated_dataset.where(cks.zip(cpks.map{|k| get_column_value(k)}))).update(ck_nil_hash)
2446       end
2447     end
2448   end
2449 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
2457 def def_one_to_one(opts)
2458   def_one_to_many(opts)
2459 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
2462 def eager_graph_dataset(opts, eager_options)
2463   ds = opts.associated_class.dataset
2464   if cb = eager_options[:callback]
2465     ds = cb.call(ds)
2466   end
2467   ds
2468 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
2472 def reload_db_schema?
2473   !@cache_associations
2474 end