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
1627 def all_association_reflections
1628   association_reflections.values
1629 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.

:eager_loading_predicate_transform

A callable object with which to transform the predicate key values used when eager loading. Called with two arguments, the array of predicate key values, and a the reflection for the association being eager loaded.

: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.

:graph_use_association_block

Makes eager_graph consider the association block. Without this, eager_graph ignores the bock and only use the :graph_* options.

: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.

:use_placeholder_loader

Whether to use a placeholder loader when eager loading the association. Can be set to false to disable the use of a placeholder loader if one would be used by default.

: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
1872 def associate(type, name, opts = OPTS, &block)
1873   raise(Error, 'invalid association type') unless assoc_class = Sequel.synchronize{ASSOCIATION_TYPES[type]}
1874   raise(Error, 'Model.associate name argument must be a symbol') unless name.is_a?(Symbol)
1875 
1876   # dup early so we don't modify opts
1877   orig_opts = opts.dup
1878 
1879   if opts[:clone]
1880     cloned_assoc = association_reflection(opts[:clone])
1881     remove_class_name = orig_opts[:class] && !orig_opts[:class_name]
1882     orig_opts = cloned_assoc[:orig_opts].merge(orig_opts)
1883     orig_opts.delete(:class_name) if remove_class_name
1884   end
1885 
1886   opts = Hash[default_association_options]
1887   if type_options = default_association_type_options[type]
1888     opts.merge!(type_options)
1889   end
1890   opts.merge!(orig_opts)
1891   opts.merge!(:type => type, :name => name, :cache=>({} if cache_associations), :model => self)
1892 
1893   opts[:block] = block if block
1894   opts[:instance_specific] = true if orig_opts[:dataset]
1895   if !opts.has_key?(:instance_specific) && (block || orig_opts[:block])
1896     # It's possible the association is instance specific, in that it depends on
1897     # values other than the foreign key value.  This needs to be checked for
1898     # in certain places to disable optimizations.
1899     opts[:instance_specific] = _association_instance_specific_default(name)
1900   end
1901   if (orig_opts[:instance_specific] || orig_opts[:dataset]) && !opts.has_key?(:allow_eager) && !opts[:eager_loader]
1902     # For associations explicitly marked as instance specific, or that use the
1903     # :dataset option, where :allow_eager is not set, and no :eager_loader is
1904     # provided, disallow eager loading.  In these cases, eager loading is
1905     # unlikely to work.  This is not done for implicit setting of :instance_specific,
1906     # because implicit use is done by default for all associations with blocks,
1907     # and the vast majority of associations with blocks use the block for filtering
1908     # in a manner compatible with eager loading.
1909     opts[:allow_eager] = false
1910   end
1911   opts = assoc_class.new.merge!(opts)
1912 
1913   if opts[:clone] && !opts.cloneable?(cloned_assoc)
1914     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]})")
1915   end
1916 
1917   opts[:use_placeholder_loader] = !opts[:instance_specific] && !opts[:eager_graph] unless opts.include?(:use_placeholder_loader)
1918   opts[:eager_block] = opts[:block] unless opts.include?(:eager_block)
1919   opts[:graph_join_type] ||= :left_outer
1920   opts[:order_eager_graph] = true unless opts.include?(:order_eager_graph)
1921   conds = opts[:conditions]
1922   opts[:graph_alias_base] ||= name
1923   opts[:graph_conditions] = conds if !opts.include?(:graph_conditions) and Sequel.condition_specifier?(conds)
1924   opts[:graph_conditions] = opts.fetch(:graph_conditions, []).to_a
1925   opts[:graph_select] = Array(opts[:graph_select]) if opts[:graph_select]
1926   [:before_add, :before_remove, :after_add, :after_remove, :after_load, :before_set, :after_set].each do |cb_type|
1927     opts[cb_type] = Array(opts[cb_type]) if opts[cb_type]
1928   end
1929 
1930   if opts[:extend]
1931     opts[:extend] = Array(opts[:extend])
1932     opts[:reverse_extend] = opts[:extend].reverse
1933   end
1934 
1935   late_binding_class_option(opts, opts.returns_array? ? singularize(name) : name)
1936   
1937   # Remove :class entry if it exists and is nil, to work with cached_fetch
1938   opts.delete(:class) unless opts[:class]
1939 
1940   opts[:_hash] = [self, name].hash
1941 
1942   def_association(opts)
1943       
1944   orig_opts.delete(:clone)
1945   opts[:orig_class] = orig_opts[:class] || orig_opts[:class_name]
1946   orig_opts.merge!(:class_name=>opts[:class_name], :class=>opts[:class], :block=>opts[:block])
1947   opts[:orig_opts] = orig_opts
1948   # don't add to association_reflections until we are sure there are no errors
1949   association_reflections[name] = opts
1950 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
1953 def association_reflection(name)
1954   association_reflections[name]
1955 end
associations() click to toggle source

Array of association name symbols

     # File lib/sequel/model/associations.rb
1958 def associations
1959   association_reflections.keys
1960 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
1963 def eager_load_results(opts, eo, &block)
1964   opts.eager_load_results(eo, &block)
1965 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
1982 def finalize_associations
1983   @association_reflections.each_value(&:finalize)
1984 end
freeze() click to toggle source

Freeze association related metadata when freezing model class.

Calls superclass method
     # File lib/sequel/model/associations.rb
1968 def freeze
1969   @association_reflections.freeze.each_value(&:freeze)
1970   @autoreloading_associations.freeze.each_value(&:freeze)
1971   @default_association_options.freeze
1972   @default_association_type_options.freeze
1973   @default_association_type_options.each_value(&:freeze)
1974 
1975   super
1976 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
1987 def many_to_many(name, opts=OPTS, &block)
1988   associate(:many_to_many, name, opts, &block)
1989 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
1992 def many_to_one(name, opts=OPTS, &block)
1993   associate(:many_to_one, name, opts, &block)
1994 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
1997 def one_through_one(name, opts=OPTS, &block)
1998   associate(:one_through_one, name, opts, &block)
1999 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
2002 def one_to_many(name, opts=OPTS, &block)
2003   associate(:one_to_many, name, opts, &block)
2004 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
2007 def one_to_one(name, opts=OPTS, &block)
2008   associate(:one_to_one, name, opts, &block)
2009 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
2018 def _association_instance_specific_default(_)
2019   true
2020 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
2024 def association_module(opts=OPTS)
2025   opts.fetch(:methods_module, overridable_methods_module)
2026 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
2031 def association_module_def(name, opts=OPTS, &block)
2032   mod = association_module(opts)
2033   mod.send(:define_method, name, &block)
2034   mod.send(:alias_method, name, name)
2035 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
2041 def association_module_delegate_def(name, opts, &block)
2042   mod = association_module(opts)
2043   mod.send(:define_method, name, &block)
2044   # :nocov:
2045   mod.send(:ruby2_keywords, name) if mod.respond_to?(:ruby2_keywords, true)
2046   # :nocov:
2047   mod.send(:alias_method, name, name)
2048 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
2051 def association_module_private_def(name, opts=OPTS, &block)
2052   association_module_def(name, opts, &block)
2053   association_module(opts).send(:private, name)
2054 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
2058 def def_association(opts)
2059   send(:"def_#{opts[:type]}", opts)
2060   def_association_instance_methods(opts)
2061 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
2071 def def_association_instance_methods(opts)
2072   # Always set the method names in the association reflection, even if they
2073   # are not used, for backwards compatibility.
2074   opts[:dataset_method] = :"#{opts[:name]}_dataset"
2075   if opts.returns_array?
2076     sname = singularize(opts[:name])
2077     opts[:_add_method] = :"_add_#{sname}"
2078     opts[:add_method] = :"add_#{sname}"
2079     opts[:_remove_method] = :"_remove_#{sname}"
2080     opts[:remove_method] = :"remove_#{sname}"
2081     opts[:_remove_all_method] = :"_remove_all_#{opts[:name]}"
2082     opts[:remove_all_method] = :"remove_all_#{opts[:name]}"
2083   else
2084     opts[:_setter_method] = :"_#{opts[:name]}="
2085     opts[:setter_method] = :"#{opts[:name]}="
2086   end
2087 
2088   association_module_def(opts.dataset_method, opts){_dataset(opts)} unless opts[:no_dataset_method]
2089   if opts[:block]
2090     opts[:block_method] = Plugins.def_sequel_method(association_module(opts), "#{opts[:name]}_block", 1, &opts[:block])
2091   end
2092   opts[:dataset_opt_arity] = opts[:dataset].arity == 0 ? 0 : 1
2093   opts[:dataset_opt_method] = Plugins.def_sequel_method(association_module(opts), "#{opts[:name]}_dataset_opt", opts[:dataset_opt_arity], &opts[:dataset])
2094   def_association_method(opts) unless opts[:no_association_method]
2095 
2096   return if opts[:read_only]
2097 
2098   if opts[:setter] && opts[:_setter]
2099     # This is backwards due to backwards compatibility
2100     association_module_private_def(opts[:_setter_method], opts, &opts[:setter])
2101     association_module_def(opts[:setter_method], opts, &opts[:_setter])
2102   end
2103 
2104   if adder = opts[:adder]
2105     association_module_private_def(opts[:_add_method], opts, &adder)
2106     association_module_delegate_def(opts[:add_method], opts){|o,*args| add_associated_object(opts, o, *args)}
2107   end
2108 
2109   if remover = opts[:remover]
2110     association_module_private_def(opts[:_remove_method], opts, &remover)
2111     association_module_delegate_def(opts[:remove_method], opts){|o,*args| remove_associated_object(opts, o, *args)}
2112   end
2113 
2114   if clearer = opts[:clearer]
2115     association_module_private_def(opts[:_remove_all_method], opts, &clearer)
2116     association_module_delegate_def(opts[:remove_all_method], opts){|*args| remove_all_associated_objects(opts, *args)}
2117   end
2118 end
def_association_method(opts) click to toggle source

Adds the association method to the association methods module.

     # File lib/sequel/model/associations.rb
2064 def def_association_method(opts)
2065   association_module_def(opts.association_method, opts) do |dynamic_opts=OPTS, &block|
2066     load_associated_objects(opts, dynamic_opts, &block)
2067   end
2068 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
2121 def def_many_to_many(opts)
2122   one_through_one = opts[:type] == :one_through_one
2123   left = (opts[:left_key] ||= opts.default_left_key)
2124   lcks = opts[:left_keys] = Array(left)
2125   right = (opts[:right_key] ||= opts.default_right_key)
2126   rcks = opts[:right_keys] = Array(right)
2127   left_pk = (opts[:left_primary_key] ||= self.primary_key)
2128   opts[:eager_loader_key] = left_pk unless opts.has_key?(:eager_loader_key)
2129   lcpks = opts[:left_primary_keys] = Array(left_pk)
2130   lpkc = opts[:left_primary_key_column] ||= left_pk
2131   lpkcs = opts[:left_primary_key_columns] ||= Array(lpkc)
2132   raise(Error, "mismatched number of left keys: #{lcks.inspect} vs #{lcpks.inspect}") unless lcks.length == lcpks.length
2133   if opts[:right_primary_key]
2134     rcpks = Array(opts[:right_primary_key])
2135     raise(Error, "mismatched number of right keys: #{rcks.inspect} vs #{rcpks.inspect}") unless rcks.length == rcpks.length
2136   end
2137   opts[:uses_left_composite_keys] = lcks.length > 1
2138   uses_rcks = opts[:uses_right_composite_keys] = rcks.length > 1
2139   opts[:cartesian_product_number] ||= one_through_one ? 0 : 1
2140   join_table = (opts[:join_table] ||= opts.default_join_table)
2141   opts[:left_key_alias] ||= opts.default_associated_key_alias
2142   opts[:graph_join_table_join_type] ||= opts[:graph_join_type]
2143   if opts[:uniq]
2144     opts[:after_load] ||= []
2145     opts[:after_load].unshift(:array_uniq!)
2146   end
2147   if join_table_db = opts[:join_table_db]
2148     opts[:use_placeholder_loader] = false
2149     opts[:allow_eager_graph] = false
2150     opts[:allow_filtering_by] = false
2151     opts[:eager_limit_strategy] = nil
2152     join_table_ds = join_table_db.from(join_table)
2153     opts[:dataset] ||= proc do |r|
2154       vals = join_table_ds.where(lcks.zip(lcpks.map{|k| get_column_value(k)})).select_map(right)
2155       ds = r.associated_dataset.where(opts.right_primary_key => vals)
2156       if uses_rcks
2157         vals.delete_if{|v| v.any?(&:nil?)}
2158       else
2159         vals.delete(nil)
2160       end
2161       ds = ds.clone(:no_results=>true) if vals.empty?
2162       ds
2163     end
2164     opts[:eager_loader] ||= proc do |eo|
2165       h = eo[:id_map]
2166       assign_singular = opts.assign_singular?
2167       rpk = opts.right_primary_key
2168       name = opts[:name]
2169 
2170       join_map = join_table_ds.where(left=>h.keys).select_hash_groups(right, left)
2171 
2172       if uses_rcks
2173         join_map.delete_if{|v,| v.any?(&:nil?)}
2174       else
2175         join_map.delete(nil)
2176       end
2177 
2178       eo = Hash[eo]
2179 
2180       if join_map.empty?
2181         eo[:no_results] = true
2182       else
2183         join_map.each_value do |vs|
2184           vs.replace(vs.flat_map{|v| h[v]})
2185           vs.uniq!
2186         end
2187 
2188         eo[:loader] = false
2189         eo[:right_keys] = join_map.keys
2190       end
2191 
2192       opts[:model].eager_load_results(opts, eo) do |assoc_record|
2193         rpkv = if uses_rcks
2194           assoc_record.values.values_at(*rpk)
2195         else
2196           assoc_record.values[rpk]
2197         end
2198 
2199         objects = join_map[rpkv]
2200 
2201         if assign_singular
2202           objects.each do |object|
2203             object.associations[name] ||= assoc_record
2204           end
2205         else
2206           objects.each do |object|
2207             object.associations[name].push(assoc_record)
2208           end
2209         end
2210       end
2211     end
2212   else
2213     opts[:dataset] ||= opts.association_dataset_proc
2214     opts[:eager_loader] ||= opts.method(:default_eager_loader)
2215   end
2216   
2217   join_type = opts[:graph_join_type]
2218   select = opts[:graph_select]
2219   use_only_conditions = opts.include?(:graph_only_conditions)
2220   only_conditions = opts[:graph_only_conditions]
2221   conditions = opts[:graph_conditions]
2222   graph_block = opts[:graph_block]
2223   graph_jt_conds = opts[:graph_join_table_conditions] = opts.fetch(:graph_join_table_conditions, []).to_a
2224   use_jt_only_conditions = opts.include?(:graph_join_table_only_conditions)
2225   jt_only_conditions = opts[:graph_join_table_only_conditions]
2226   jt_join_type = opts[:graph_join_table_join_type]
2227   jt_graph_block = opts[:graph_join_table_block]
2228   opts[:eager_grapher] ||= proc do |eo|
2229     ds = eo[:self]
2230     egls = eo[:limit_strategy]
2231     if egls && egls != :ruby
2232       associated_key_array = opts.associated_key_array
2233       orig_egds = egds = eager_graph_dataset(opts, eo)
2234       egds = egds.
2235         inner_join(join_table, rcks.zip(opts.right_primary_keys) + graph_jt_conds, :qualify=>:deep).
2236         select_all(egds.first_source).
2237         select_append(*associated_key_array)
2238       egds = opts.apply_eager_graph_limit_strategy(egls, egds)
2239       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)
2240     else
2241       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)
2242       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)
2243     end
2244   end
2245       
2246   return if opts[:read_only]
2247       
2248   if one_through_one
2249     unless opts.has_key?(:setter)
2250       opts[:setter] = proc do |o|
2251         h = {}
2252         lh = lcks.zip(lcpks.map{|k| get_column_value(k)})
2253         jtds = _join_table_dataset(opts).where(lh)
2254 
2255         checked_transaction do
2256           current = jtds.first
2257 
2258           if o
2259             new_values = []
2260             rcks.zip(opts.right_primary_key_methods).each{|k, pk| new_values << (h[k] = o.get_column_value(pk))}
2261           end
2262 
2263           if current
2264             current_values = rcks.map{|k| current[k]}
2265             jtds = jtds.where(rcks.zip(current_values))
2266             if o
2267               if current_values != new_values
2268                 jtds.update(h)
2269               end
2270             else
2271               jtds.delete
2272             end
2273           elsif o
2274             lh.each{|k,v| h[k] = v}
2275             jtds.insert(h)
2276           end
2277         end
2278       end
2279     end
2280     if opts.fetch(:setter, true)
2281       opts[:_setter] = proc{|o| set_one_through_one_associated_object(opts, o)}
2282     end
2283   else 
2284     unless opts.has_key?(:adder)
2285       opts[:adder] = proc do |o|
2286         h = {}
2287         lcks.zip(lcpks).each{|k, pk| h[k] = get_column_value(pk)}
2288         rcks.zip(opts.right_primary_key_methods).each{|k, pk| h[k] = o.get_column_value(pk)}
2289         _join_table_dataset(opts).insert(h)
2290       end
2291     end
2292 
2293     unless opts.has_key?(:remover)
2294       opts[:remover] = proc do |o|
2295         _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
2296       end
2297     end
2298 
2299     unless opts.has_key?(:clearer)
2300       opts[:clearer] = proc do
2301         _join_table_dataset(opts).where(lcks.zip(lcpks.map{|k| get_column_value(k)})).delete
2302       end
2303     end
2304   end
2305 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
2308 def def_many_to_one(opts)
2309   name = opts[:name]
2310   opts[:key] = opts.default_key unless opts.has_key?(:key)
2311   key = opts[:key]
2312   opts[:eager_loader_key] = key unless opts.has_key?(:eager_loader_key)
2313   cks = opts[:graph_keys] = opts[:keys] = Array(key)
2314   opts[:key_column] ||= key
2315   opts[:graph_keys] = opts[:key_columns] = Array(opts[:key_column])
2316   opts[:qualified_key] = opts.qualify_cur(key)
2317   if opts[:primary_key]
2318     cpks = Array(opts[:primary_key])
2319     raise(Error, "mismatched number of keys: #{cks.inspect} vs #{cpks.inspect}") unless cks.length == cpks.length
2320   end
2321   uses_cks = opts[:uses_composite_keys] = cks.length > 1
2322   opts[:cartesian_product_number] ||= 0
2323 
2324   if !opts.has_key?(:many_to_one_pk_lookup) &&
2325      (opts[:dataset] || opts[:conditions] || opts[:block] || opts[:select] ||
2326       (opts.has_key?(:key) && opts[:key] == nil))
2327     opts[:many_to_one_pk_lookup] = false
2328   end
2329   auto_assocs = @autoreloading_associations
2330   cks.each do |k|
2331     (auto_assocs[k] ||= []) << name
2332   end
2333 
2334   opts[:dataset] ||= opts.association_dataset_proc
2335   opts[:eager_loader] ||= proc do |eo|
2336     h = eo[:id_map]
2337     pk_meths = opts.primary_key_methods
2338 
2339     eager_load_results(opts, eo) do |assoc_record|
2340       hash_key = uses_cks ? pk_meths.map{|k| assoc_record.get_column_value(k)} : assoc_record.get_column_value(opts.primary_key_method)
2341       h[hash_key].each{|object| object.associations[name] = assoc_record}
2342     end
2343   end
2344       
2345   join_type = opts[:graph_join_type]
2346   select = opts[:graph_select]
2347   use_only_conditions = opts.include?(:graph_only_conditions)
2348   only_conditions = opts[:graph_only_conditions]
2349   conditions = opts[:graph_conditions]
2350   graph_block = opts[:graph_block]
2351   graph_cks = opts[:graph_keys]
2352   opts[:eager_grapher] ||= proc do |eo|
2353     ds = eo[:self]
2354     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)
2355   end
2356       
2357   return if opts[:read_only]
2358       
2359   unless opts.has_key?(:setter)
2360     opts[:setter] = proc{|o| cks.zip(opts.primary_key_methods).each{|k, pk| set_column_value(:"#{k}=", (o.get_column_value(pk) if o))}}
2361   end
2362   if opts.fetch(:setter, true)
2363     opts[:_setter] = proc{|o| set_associated_object(opts, o)}
2364   end
2365 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
2489 def def_one_through_one(opts)
2490   def_many_to_many(opts)
2491 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
2368 def def_one_to_many(opts)
2369   one_to_one = opts[:type] == :one_to_one
2370   name = opts[:name]
2371   key = (opts[:key] ||= opts.default_key)
2372   km = opts[:key_method] ||= opts[:key]
2373   cks = opts[:keys] = Array(key)
2374   opts[:key_methods] = Array(opts[:key_method])
2375   primary_key = (opts[:primary_key] ||= self.primary_key)
2376   opts[:eager_loader_key] = primary_key unless opts.has_key?(:eager_loader_key)
2377   cpks = opts[:primary_keys] = Array(primary_key)
2378   pkc = opts[:primary_key_column] ||= primary_key
2379   pkcs = opts[:primary_key_columns] ||= Array(pkc)
2380   raise(Error, "mismatched number of keys: #{cks.inspect} vs #{cpks.inspect}") unless cks.length == cpks.length
2381   uses_cks = opts[:uses_composite_keys] = cks.length > 1
2382   opts[:dataset] ||= opts.association_dataset_proc
2383   opts[:eager_loader] ||= proc do |eo|
2384     h = eo[:id_map]
2385     reciprocal = opts.reciprocal
2386     assign_singular = opts.assign_singular?
2387     delete_rn = opts.delete_row_number_column
2388 
2389     eager_load_results(opts, eo) do |assoc_record|
2390       assoc_record.values.delete(delete_rn) if delete_rn
2391       hash_key = uses_cks ? km.map{|k| assoc_record.get_column_value(k)} : assoc_record.get_column_value(km)
2392       objects = h[hash_key]
2393       if assign_singular
2394         objects.each do |object| 
2395           unless object.associations[name]
2396             object.associations[name] = assoc_record
2397             assoc_record.associations[reciprocal] = object if reciprocal
2398           end
2399         end
2400       else
2401         objects.each do |object| 
2402           object.associations[name].push(assoc_record)
2403           assoc_record.associations[reciprocal] = object if reciprocal
2404         end
2405       end
2406     end
2407   end
2408   
2409   join_type = opts[:graph_join_type]
2410   select = opts[:graph_select]
2411   use_only_conditions = opts.include?(:graph_only_conditions)
2412   only_conditions = opts[:graph_only_conditions]
2413   conditions = opts[:graph_conditions]
2414   opts[:cartesian_product_number] ||= one_to_one ? 0 : 1
2415   graph_block = opts[:graph_block]
2416   opts[:eager_grapher] ||= proc do |eo|
2417     ds = eo[:self]
2418     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)
2419     # We only load reciprocals for one_to_many associations, as other reciprocals don't make sense
2420     ds.opts[:eager_graph][:reciprocals][eo[:table_alias]] = opts.reciprocal
2421     ds
2422   end
2423       
2424   return if opts[:read_only]
2425 
2426   save_opts = {:validate=>opts[:validate]}
2427   ck_nil_hash ={}
2428   cks.each{|k| ck_nil_hash[k] = nil}
2429 
2430   if one_to_one
2431     unless opts.has_key?(:setter)
2432       opts[:setter] = proc do |o|
2433         up_ds = _apply_association_options(opts, opts.associated_dataset.where(cks.zip(cpks.map{|k| get_column_value(k)})))
2434 
2435         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)))
2436           if old = up_ds.first
2437             cks.each{|k| old.set_column_value(:"#{k}=", nil)}
2438           end
2439           save_old = true
2440         end
2441 
2442         if o
2443           if !o.new? && !save_old
2444             up_ds = up_ds.exclude(o.pk_hash)
2445           end
2446           cks.zip(cpks).each{|k, pk| o.set_column_value(:"#{k}=", get_column_value(pk))}
2447         end
2448 
2449         checked_transaction do
2450           if save_old
2451             old.save(save_opts) || raise(Sequel::Error, "invalid previously associated object, cannot save") if old
2452           else
2453             up_ds.skip_limit_check.update(ck_nil_hash)
2454           end
2455 
2456           o.save(save_opts) || raise(Sequel::Error, "invalid associated object, cannot save") if o
2457         end
2458       end
2459     end
2460     if opts.fetch(:setter, true)
2461       opts[:_setter] = proc{|o| set_one_to_one_associated_object(opts, o)}
2462     end
2463   else 
2464     save_opts[:raise_on_failure] = opts[:raise_on_save_failure] != false
2465 
2466     unless opts.has_key?(:adder)
2467       opts[:adder] = proc do |o|
2468         cks.zip(cpks).each{|k, pk| o.set_column_value(:"#{k}=", get_column_value(pk))}
2469         o.save(save_opts)
2470       end
2471     end
2472     
2473     unless opts.has_key?(:remover)
2474       opts[:remover] = proc do |o|
2475         cks.each{|k| o.set_column_value(:"#{k}=", nil)}
2476         o.save(save_opts)
2477       end
2478     end
2479 
2480     unless opts.has_key?(:clearer)
2481       opts[:clearer] = proc do
2482         _apply_association_options(opts, opts.associated_dataset.where(cks.zip(cpks.map{|k| get_column_value(k)}))).update(ck_nil_hash)
2483       end
2484     end
2485   end
2486 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
2494 def def_one_to_one(opts)
2495   def_one_to_many(opts)
2496 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
2499 def eager_graph_dataset(opts, eager_options)
2500   ds = opts.associated_class.dataset
2501   if opts[:graph_use_association_block] && (b = opts[:block])
2502     ds = b.call(ds)
2503   end
2504   if cb = eager_options[:callback]
2505     ds = cb.call(ds)
2506   end
2507   ds
2508 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
2512 def reload_db_schema?
2513   !@cache_associations
2514 end