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
All association reflections defined for this model (default: {}).
Hash
with column symbol keys and arrays of many_to_one
association symbols that should be cleared when the column value changes.
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.
The default options to use for all associations. This hash is merged into the association reflection hash for all association reflections.
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.
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
Array
of all association reflections for this model class
# File lib/sequel/model/associations.rb 1595 def all_association_reflections 1596 association_reflections.values 1597 end
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 tomany_to_one
, except that theone_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
, andone_through_one
associations, 1 forone_to_many
andmany_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 viaeager
. - :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 viaeager_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 viaeager_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. - :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
orone_to_one
associations), or add_/remove_/remove_all_ methods (forone_to_many
andmany_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 viaeager_graph
. - :graph_join_table_conditions
-
The additional conditions to use on the
SQL
join for the join table when eagerly loading the association viaeager_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 viaeager_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 viaeager_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 givenDatabase
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 1830 def associate(type, name, opts = OPTS, &block) 1831 raise(Error, 'invalid association type') unless assoc_class = Sequel.synchronize{ASSOCIATION_TYPES[type]} 1832 raise(Error, 'Model.associate name argument must be a symbol') unless name.is_a?(Symbol) 1833 1834 # dup early so we don't modify opts 1835 orig_opts = opts.dup 1836 1837 if opts[:clone] 1838 cloned_assoc = association_reflection(opts[:clone]) 1839 orig_opts = cloned_assoc[:orig_opts].merge(orig_opts) 1840 end 1841 1842 opts = Hash[default_association_options] 1843 if type_options = default_association_type_options[type] 1844 opts.merge!(type_options) 1845 end 1846 opts.merge!(orig_opts) 1847 opts.merge!(:type => type, :name => name, :cache=>({} if cache_associations), :model => self) 1848 1849 opts[:block] = block if block 1850 opts[:instance_specific] = true if orig_opts[:dataset] 1851 if !opts.has_key?(:instance_specific) && (block || orig_opts[:block]) 1852 # It's possible the association is instance specific, in that it depends on 1853 # values other than the foreign key value. This needs to be checked for 1854 # in certain places to disable optimizations. 1855 opts[:instance_specific] = _association_instance_specific_default(name) 1856 end 1857 opts = assoc_class.new.merge!(opts) 1858 1859 if opts[:clone] && !opts.cloneable?(cloned_assoc) 1860 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]})") 1861 end 1862 1863 opts[:use_placeholder_loader] = !opts[:instance_specific] && !opts[:eager_graph] 1864 opts[:eager_block] = opts[:block] unless opts.include?(:eager_block) 1865 opts[:graph_join_type] ||= :left_outer 1866 opts[:order_eager_graph] = true unless opts.include?(:order_eager_graph) 1867 conds = opts[:conditions] 1868 opts[:graph_alias_base] ||= name 1869 opts[:graph_conditions] = conds if !opts.include?(:graph_conditions) and Sequel.condition_specifier?(conds) 1870 opts[:graph_conditions] = opts.fetch(:graph_conditions, []).to_a 1871 opts[:graph_select] = Array(opts[:graph_select]) if opts[:graph_select] 1872 [:before_add, :before_remove, :after_add, :after_remove, :after_load, :before_set, :after_set].each do |cb_type| 1873 opts[cb_type] = Array(opts[cb_type]) if opts[cb_type] 1874 end 1875 1876 if opts[:extend] 1877 opts[:extend] = Array(opts[:extend]) 1878 opts[:reverse_extend] = opts[:extend].reverse 1879 end 1880 1881 late_binding_class_option(opts, opts.returns_array? ? singularize(name) : name) 1882 1883 # Remove :class entry if it exists and is nil, to work with cached_fetch 1884 opts.delete(:class) unless opts[:class] 1885 1886 def_association(opts) 1887 1888 orig_opts.delete(:clone) 1889 opts[:orig_class] = orig_opts[:class] || orig_opts[:class_name] 1890 orig_opts.merge!(:class_name=>opts[:class_name], :class=>opts[:class], :block=>opts[:block]) 1891 opts[:orig_opts] = orig_opts 1892 # don't add to association_reflections until we are sure there are no errors 1893 association_reflections[name] = opts 1894 end
The association reflection hash for the association of the given name.
# File lib/sequel/model/associations.rb 1897 def association_reflection(name) 1898 association_reflections[name] 1899 end
Array
of association name symbols
# File lib/sequel/model/associations.rb 1902 def associations 1903 association_reflections.keys 1904 end
Eager load the association with the given eager loader options.
# File lib/sequel/model/associations.rb 1907 def eager_load_results(opts, eo, &block) 1908 opts.eager_load_results(eo, &block) 1909 end
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 1926 def finalize_associations 1927 @association_reflections.each_value(&:finalize) 1928 end
Freeze association related metadata when freezing model class.
# File lib/sequel/model/associations.rb 1912 def freeze 1913 @association_reflections.freeze.each_value(&:freeze) 1914 @autoreloading_associations.freeze.each_value(&:freeze) 1915 @default_association_options.freeze 1916 @default_association_type_options.freeze 1917 @default_association_type_options.each_value(&:freeze) 1918 1919 super 1920 end
Shortcut for adding a many_to_many
association, see associate
# File lib/sequel/model/associations.rb 1931 def many_to_many(name, opts=OPTS, &block) 1932 associate(:many_to_many, name, opts, &block) 1933 end
Shortcut for adding a many_to_one
association, see associate
# File lib/sequel/model/associations.rb 1936 def many_to_one(name, opts=OPTS, &block) 1937 associate(:many_to_one, name, opts, &block) 1938 end
Shortcut for adding a one_through_one
association, see associate
# File lib/sequel/model/associations.rb 1941 def one_through_one(name, opts=OPTS, &block) 1942 associate(:one_through_one, name, opts, &block) 1943 end
Shortcut for adding a one_to_many
association, see associate
# File lib/sequel/model/associations.rb 1946 def one_to_many(name, opts=OPTS, &block) 1947 associate(:one_to_many, name, opts, &block) 1948 end
Shortcut for adding a one_to_one
association, see associate
# File lib/sequel/model/associations.rb 1951 def one_to_one(name, opts=OPTS, &block) 1952 associate(:one_to_one, name, opts, &block) 1953 end
Private Instance Methods
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 1962 def _association_instance_specific_default(_) 1963 true 1964 end
The module to use for the association's methods. Defaults to the overridable_methods_module.
# File lib/sequel/model/associations.rb 1968 def association_module(opts=OPTS) 1969 opts.fetch(:methods_module, overridable_methods_module) 1970 end
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 1975 def association_module_def(name, opts=OPTS, &block) 1976 mod = association_module(opts) 1977 mod.send(:define_method, name, &block) 1978 mod.send(:alias_method, name, name) 1979 end
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 1985 def association_module_delegate_def(name, opts, &block) 1986 mod = association_module(opts) 1987 mod.send(:define_method, name, &block) 1988 # :nocov: 1989 mod.send(:ruby2_keywords, name) if mod.respond_to?(:ruby2_keywords, true) 1990 # :nocov: 1991 mod.send(:alias_method, name, name) 1992 end
Add a private method to the module included in the class.
# File lib/sequel/model/associations.rb 1995 def association_module_private_def(name, opts=OPTS, &block) 1996 association_module_def(name, opts, &block) 1997 association_module(opts).send(:private, name) 1998 end
Delegate to the type-specific association method to setup the association, and define the association instance methods.
# File lib/sequel/model/associations.rb 2002 def def_association(opts) 2003 send(:"def_#{opts[:type]}", opts) 2004 def_association_instance_methods(opts) 2005 end
Define all of the association instance methods for this association.
# File lib/sequel/model/associations.rb 2015 def def_association_instance_methods(opts) 2016 # Always set the method names in the association reflection, even if they 2017 # are not used, for backwards compatibility. 2018 opts[:dataset_method] = :"#{opts[:name]}_dataset" 2019 if opts.returns_array? 2020 sname = singularize(opts[:name]) 2021 opts[:_add_method] = :"_add_#{sname}" 2022 opts[:add_method] = :"add_#{sname}" 2023 opts[:_remove_method] = :"_remove_#{sname}" 2024 opts[:remove_method] = :"remove_#{sname}" 2025 opts[:_remove_all_method] = :"_remove_all_#{opts[:name]}" 2026 opts[:remove_all_method] = :"remove_all_#{opts[:name]}" 2027 else 2028 opts[:_setter_method] = :"_#{opts[:name]}=" 2029 opts[:setter_method] = :"#{opts[:name]}=" 2030 end 2031 2032 association_module_def(opts.dataset_method, opts){_dataset(opts)} unless opts[:no_dataset_method] 2033 if opts[:block] 2034 opts[:block_method] = Plugins.def_sequel_method(association_module(opts), "#{opts[:name]}_block", 1, &opts[:block]) 2035 end 2036 opts[:dataset_opt_arity] = opts[:dataset].arity == 0 ? 0 : 1 2037 opts[:dataset_opt_method] = Plugins.def_sequel_method(association_module(opts), "#{opts[:name]}_dataset_opt", opts[:dataset_opt_arity], &opts[:dataset]) 2038 def_association_method(opts) unless opts[:no_association_method] 2039 2040 return if opts[:read_only] 2041 2042 if opts[:setter] && opts[:_setter] 2043 # This is backwards due to backwards compatibility 2044 association_module_private_def(opts[:_setter_method], opts, &opts[:setter]) 2045 association_module_def(opts[:setter_method], opts, &opts[:_setter]) 2046 end 2047 2048 if adder = opts[:adder] 2049 association_module_private_def(opts[:_add_method], opts, &adder) 2050 association_module_delegate_def(opts[:add_method], opts){|o,*args| add_associated_object(opts, o, *args)} 2051 end 2052 2053 if remover = opts[:remover] 2054 association_module_private_def(opts[:_remove_method], opts, &remover) 2055 association_module_delegate_def(opts[:remove_method], opts){|o,*args| remove_associated_object(opts, o, *args)} 2056 end 2057 2058 if clearer = opts[:clearer] 2059 association_module_private_def(opts[:_remove_all_method], opts, &clearer) 2060 association_module_delegate_def(opts[:remove_all_method], opts){|*args| remove_all_associated_objects(opts, *args)} 2061 end 2062 end
Adds the association method to the association methods module.
# File lib/sequel/model/associations.rb 2008 def def_association_method(opts) 2009 association_module_def(opts.association_method, opts) do |dynamic_opts=OPTS, &block| 2010 load_associated_objects(opts, dynamic_opts, &block) 2011 end 2012 end
Configures many_to_many
and one_through_one
association reflection and adds the related association methods
# File lib/sequel/model/associations.rb 2065 def def_many_to_many(opts) 2066 one_through_one = opts[:type] == :one_through_one 2067 left = (opts[:left_key] ||= opts.default_left_key) 2068 lcks = opts[:left_keys] = Array(left) 2069 right = (opts[:right_key] ||= opts.default_right_key) 2070 rcks = opts[:right_keys] = Array(right) 2071 left_pk = (opts[:left_primary_key] ||= self.primary_key) 2072 opts[:eager_loader_key] = left_pk unless opts.has_key?(:eager_loader_key) 2073 lcpks = opts[:left_primary_keys] = Array(left_pk) 2074 lpkc = opts[:left_primary_key_column] ||= left_pk 2075 lpkcs = opts[:left_primary_key_columns] ||= Array(lpkc) 2076 raise(Error, "mismatched number of left keys: #{lcks.inspect} vs #{lcpks.inspect}") unless lcks.length == lcpks.length 2077 if opts[:right_primary_key] 2078 rcpks = Array(opts[:right_primary_key]) 2079 raise(Error, "mismatched number of right keys: #{rcks.inspect} vs #{rcpks.inspect}") unless rcks.length == rcpks.length 2080 end 2081 opts[:uses_left_composite_keys] = lcks.length > 1 2082 uses_rcks = opts[:uses_right_composite_keys] = rcks.length > 1 2083 opts[:cartesian_product_number] ||= one_through_one ? 0 : 1 2084 join_table = (opts[:join_table] ||= opts.default_join_table) 2085 opts[:left_key_alias] ||= opts.default_associated_key_alias 2086 opts[:graph_join_table_join_type] ||= opts[:graph_join_type] 2087 if opts[:uniq] 2088 opts[:after_load] ||= [] 2089 opts[:after_load].unshift(:array_uniq!) 2090 end 2091 if join_table_db = opts[:join_table_db] 2092 opts[:use_placeholder_loader] = false 2093 opts[:allow_eager_graph] = false 2094 opts[:allow_filtering_by] = false 2095 opts[:eager_limit_strategy] = nil 2096 join_table_ds = join_table_db.from(join_table) 2097 opts[:dataset] ||= proc do |r| 2098 vals = join_table_ds.where(lcks.zip(lcpks.map{|k| get_column_value(k)})).select_map(right) 2099 ds = r.associated_dataset.where(opts.right_primary_key => vals) 2100 if uses_rcks 2101 vals.delete_if{|v| v.any?(&:nil?)} 2102 else 2103 vals.delete(nil) 2104 end 2105 ds = ds.clone(:no_results=>true) if vals.empty? 2106 ds 2107 end 2108 opts[:eager_loader] ||= proc do |eo| 2109 h = eo[:id_map] 2110 assign_singular = opts.assign_singular? 2111 rpk = opts.right_primary_key 2112 name = opts[:name] 2113 2114 join_map = join_table_ds.where(left=>h.keys).select_hash_groups(right, left) 2115 2116 if uses_rcks 2117 join_map.delete_if{|v,| v.any?(&:nil?)} 2118 else 2119 join_map.delete(nil) 2120 end 2121 2122 eo = Hash[eo] 2123 2124 if join_map.empty? 2125 eo[:no_results] = true 2126 else 2127 join_map.each_value do |vs| 2128 vs.replace(vs.flat_map{|v| h[v]}) 2129 vs.uniq! 2130 end 2131 2132 eo[:loader] = false 2133 eo[:right_keys] = join_map.keys 2134 end 2135 2136 opts[:model].eager_load_results(opts, eo) do |assoc_record| 2137 rpkv = if uses_rcks 2138 assoc_record.values.values_at(*rpk) 2139 else 2140 assoc_record.values[rpk] 2141 end 2142 2143 objects = join_map[rpkv] 2144 2145 if assign_singular 2146 objects.each do |object| 2147 object.associations[name] ||= assoc_record 2148 end 2149 else 2150 objects.each do |object| 2151 object.associations[name].push(assoc_record) 2152 end 2153 end 2154 end 2155 end 2156 else 2157 opts[:dataset] ||= opts.association_dataset_proc 2158 opts[:eager_loader] ||= opts.method(:default_eager_loader) 2159 end 2160 2161 join_type = opts[:graph_join_type] 2162 select = opts[:graph_select] 2163 use_only_conditions = opts.include?(:graph_only_conditions) 2164 only_conditions = opts[:graph_only_conditions] 2165 conditions = opts[:graph_conditions] 2166 graph_block = opts[:graph_block] 2167 graph_jt_conds = opts[:graph_join_table_conditions] = opts.fetch(:graph_join_table_conditions, []).to_a 2168 use_jt_only_conditions = opts.include?(:graph_join_table_only_conditions) 2169 jt_only_conditions = opts[:graph_join_table_only_conditions] 2170 jt_join_type = opts[:graph_join_table_join_type] 2171 jt_graph_block = opts[:graph_join_table_block] 2172 opts[:eager_grapher] ||= proc do |eo| 2173 ds = eo[:self] 2174 egls = eo[:limit_strategy] 2175 if egls && egls != :ruby 2176 associated_key_array = opts.associated_key_array 2177 orig_egds = egds = eager_graph_dataset(opts, eo) 2178 egds = egds. 2179 inner_join(join_table, rcks.zip(opts.right_primary_keys) + graph_jt_conds, :qualify=>:deep). 2180 select_all(egds.first_source). 2181 select_append(*associated_key_array) 2182 egds = opts.apply_eager_graph_limit_strategy(egls, egds) 2183 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) 2184 else 2185 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) 2186 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) 2187 end 2188 end 2189 2190 return if opts[:read_only] 2191 2192 if one_through_one 2193 unless opts.has_key?(:setter) 2194 opts[:setter] = proc do |o| 2195 h = {} 2196 lh = lcks.zip(lcpks.map{|k| get_column_value(k)}) 2197 jtds = _join_table_dataset(opts).where(lh) 2198 2199 checked_transaction do 2200 current = jtds.first 2201 2202 if o 2203 new_values = [] 2204 rcks.zip(opts.right_primary_key_methods).each{|k, pk| new_values << (h[k] = o.get_column_value(pk))} 2205 end 2206 2207 if current 2208 current_values = rcks.map{|k| current[k]} 2209 jtds = jtds.where(rcks.zip(current_values)) 2210 if o 2211 if current_values != new_values 2212 jtds.update(h) 2213 end 2214 else 2215 jtds.delete 2216 end 2217 elsif o 2218 lh.each{|k,v| h[k] = v} 2219 jtds.insert(h) 2220 end 2221 end 2222 end 2223 end 2224 if opts.fetch(:setter, true) 2225 opts[:_setter] = proc{|o| set_one_through_one_associated_object(opts, o)} 2226 end 2227 else 2228 unless opts.has_key?(:adder) 2229 opts[:adder] = proc do |o| 2230 h = {} 2231 lcks.zip(lcpks).each{|k, pk| h[k] = get_column_value(pk)} 2232 rcks.zip(opts.right_primary_key_methods).each{|k, pk| h[k] = o.get_column_value(pk)} 2233 _join_table_dataset(opts).insert(h) 2234 end 2235 end 2236 2237 unless opts.has_key?(:remover) 2238 opts[:remover] = proc do |o| 2239 _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 2240 end 2241 end 2242 2243 unless opts.has_key?(:clearer) 2244 opts[:clearer] = proc do 2245 _join_table_dataset(opts).where(lcks.zip(lcpks.map{|k| get_column_value(k)})).delete 2246 end 2247 end 2248 end 2249 end
Configures many_to_one
association reflection and adds the related association methods
# File lib/sequel/model/associations.rb 2252 def def_many_to_one(opts) 2253 name = opts[:name] 2254 opts[:key] = opts.default_key unless opts.has_key?(:key) 2255 key = opts[:key] 2256 opts[:eager_loader_key] = key unless opts.has_key?(:eager_loader_key) 2257 cks = opts[:graph_keys] = opts[:keys] = Array(key) 2258 opts[:key_column] ||= key 2259 opts[:graph_keys] = opts[:key_columns] = Array(opts[:key_column]) 2260 opts[:qualified_key] = opts.qualify_cur(key) 2261 if opts[:primary_key] 2262 cpks = Array(opts[:primary_key]) 2263 raise(Error, "mismatched number of keys: #{cks.inspect} vs #{cpks.inspect}") unless cks.length == cpks.length 2264 end 2265 uses_cks = opts[:uses_composite_keys] = cks.length > 1 2266 opts[:cartesian_product_number] ||= 0 2267 2268 if !opts.has_key?(:many_to_one_pk_lookup) && 2269 (opts[:dataset] || opts[:conditions] || opts[:block] || opts[:select] || 2270 (opts.has_key?(:key) && opts[:key] == nil)) 2271 opts[:many_to_one_pk_lookup] = false 2272 end 2273 auto_assocs = @autoreloading_associations 2274 cks.each do |k| 2275 (auto_assocs[k] ||= []) << name 2276 end 2277 2278 opts[:dataset] ||= opts.association_dataset_proc 2279 opts[:eager_loader] ||= proc do |eo| 2280 h = eo[:id_map] 2281 pk_meths = opts.primary_key_methods 2282 2283 eager_load_results(opts, eo) do |assoc_record| 2284 hash_key = uses_cks ? pk_meths.map{|k| assoc_record.get_column_value(k)} : assoc_record.get_column_value(opts.primary_key_method) 2285 h[hash_key].each{|object| object.associations[name] = assoc_record} 2286 end 2287 end 2288 2289 join_type = opts[:graph_join_type] 2290 select = opts[:graph_select] 2291 use_only_conditions = opts.include?(:graph_only_conditions) 2292 only_conditions = opts[:graph_only_conditions] 2293 conditions = opts[:graph_conditions] 2294 graph_block = opts[:graph_block] 2295 graph_cks = opts[:graph_keys] 2296 opts[:eager_grapher] ||= proc do |eo| 2297 ds = eo[:self] 2298 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) 2299 end 2300 2301 return if opts[:read_only] 2302 2303 unless opts.has_key?(:setter) 2304 opts[:setter] = proc{|o| cks.zip(opts.primary_key_methods).each{|k, pk| set_column_value(:"#{k}=", (o.get_column_value(pk) if o))}} 2305 end 2306 if opts.fetch(:setter, true) 2307 opts[:_setter] = proc{|o| set_associated_object(opts, o)} 2308 end 2309 end
Alias of def_many_to_many
, since they share pretty much the same code.
# File lib/sequel/model/associations.rb 2433 def def_one_through_one(opts) 2434 def_many_to_many(opts) 2435 end
Configures one_to_many
and one_to_one
association reflections and adds the related association methods
# File lib/sequel/model/associations.rb 2312 def def_one_to_many(opts) 2313 one_to_one = opts[:type] == :one_to_one 2314 name = opts[:name] 2315 key = (opts[:key] ||= opts.default_key) 2316 km = opts[:key_method] ||= opts[:key] 2317 cks = opts[:keys] = Array(key) 2318 opts[:key_methods] = Array(opts[:key_method]) 2319 primary_key = (opts[:primary_key] ||= self.primary_key) 2320 opts[:eager_loader_key] = primary_key unless opts.has_key?(:eager_loader_key) 2321 cpks = opts[:primary_keys] = Array(primary_key) 2322 pkc = opts[:primary_key_column] ||= primary_key 2323 pkcs = opts[:primary_key_columns] ||= Array(pkc) 2324 raise(Error, "mismatched number of keys: #{cks.inspect} vs #{cpks.inspect}") unless cks.length == cpks.length 2325 uses_cks = opts[:uses_composite_keys] = cks.length > 1 2326 opts[:dataset] ||= opts.association_dataset_proc 2327 opts[:eager_loader] ||= proc do |eo| 2328 h = eo[:id_map] 2329 reciprocal = opts.reciprocal 2330 assign_singular = opts.assign_singular? 2331 delete_rn = opts.delete_row_number_column 2332 2333 eager_load_results(opts, eo) do |assoc_record| 2334 assoc_record.values.delete(delete_rn) if delete_rn 2335 hash_key = uses_cks ? km.map{|k| assoc_record.get_column_value(k)} : assoc_record.get_column_value(km) 2336 objects = h[hash_key] 2337 if assign_singular 2338 objects.each do |object| 2339 unless object.associations[name] 2340 object.associations[name] = assoc_record 2341 assoc_record.associations[reciprocal] = object if reciprocal 2342 end 2343 end 2344 else 2345 objects.each do |object| 2346 object.associations[name].push(assoc_record) 2347 assoc_record.associations[reciprocal] = object if reciprocal 2348 end 2349 end 2350 end 2351 end 2352 2353 join_type = opts[:graph_join_type] 2354 select = opts[:graph_select] 2355 use_only_conditions = opts.include?(:graph_only_conditions) 2356 only_conditions = opts[:graph_only_conditions] 2357 conditions = opts[:graph_conditions] 2358 opts[:cartesian_product_number] ||= one_to_one ? 0 : 1 2359 graph_block = opts[:graph_block] 2360 opts[:eager_grapher] ||= proc do |eo| 2361 ds = eo[:self] 2362 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) 2363 # We only load reciprocals for one_to_many associations, as other reciprocals don't make sense 2364 ds.opts[:eager_graph][:reciprocals][eo[:table_alias]] = opts.reciprocal 2365 ds 2366 end 2367 2368 return if opts[:read_only] 2369 2370 save_opts = {:validate=>opts[:validate]} 2371 ck_nil_hash ={} 2372 cks.each{|k| ck_nil_hash[k] = nil} 2373 2374 if one_to_one 2375 unless opts.has_key?(:setter) 2376 opts[:setter] = proc do |o| 2377 up_ds = _apply_association_options(opts, opts.associated_dataset.where(cks.zip(cpks.map{|k| get_column_value(k)}))) 2378 2379 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))) 2380 if old = up_ds.first 2381 cks.each{|k| old.set_column_value(:"#{k}=", nil)} 2382 end 2383 save_old = true 2384 end 2385 2386 if o 2387 if !o.new? && !save_old 2388 up_ds = up_ds.exclude(o.pk_hash) 2389 end 2390 cks.zip(cpks).each{|k, pk| o.set_column_value(:"#{k}=", get_column_value(pk))} 2391 end 2392 2393 checked_transaction do 2394 if save_old 2395 old.save(save_opts) || raise(Sequel::Error, "invalid previously associated object, cannot save") if old 2396 else 2397 up_ds.skip_limit_check.update(ck_nil_hash) 2398 end 2399 2400 o.save(save_opts) || raise(Sequel::Error, "invalid associated object, cannot save") if o 2401 end 2402 end 2403 end 2404 if opts.fetch(:setter, true) 2405 opts[:_setter] = proc{|o| set_one_to_one_associated_object(opts, o)} 2406 end 2407 else 2408 save_opts[:raise_on_failure] = opts[:raise_on_save_failure] != false 2409 2410 unless opts.has_key?(:adder) 2411 opts[:adder] = proc do |o| 2412 cks.zip(cpks).each{|k, pk| o.set_column_value(:"#{k}=", get_column_value(pk))} 2413 o.save(save_opts) 2414 end 2415 end 2416 2417 unless opts.has_key?(:remover) 2418 opts[:remover] = proc do |o| 2419 cks.each{|k| o.set_column_value(:"#{k}=", nil)} 2420 o.save(save_opts) 2421 end 2422 end 2423 2424 unless opts.has_key?(:clearer) 2425 opts[:clearer] = proc do 2426 _apply_association_options(opts, opts.associated_dataset.where(cks.zip(cpks.map{|k| get_column_value(k)}))).update(ck_nil_hash) 2427 end 2428 end 2429 end 2430 end
Alias of def_one_to_many
, since they share pretty much the same code.
# File lib/sequel/model/associations.rb 2438 def def_one_to_one(opts) 2439 def_one_to_many(opts) 2440 end
Return dataset to graph into given the association reflection, applying the :callback option if set.
# File lib/sequel/model/associations.rb 2443 def eager_graph_dataset(opts, eager_options) 2444 ds = opts.associated_class.dataset 2445 if cb = eager_options[:callback] 2446 ds = cb.call(ds) 2447 end 2448 ds 2449 end
If not caching associations, reload the database schema by default, ignoring any cached values.
# File lib/sequel/model/associations.rb 2453 def reload_db_schema? 2454 !@cache_associations 2455 end