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
1595 def all_association_reflections
1596   association_reflections.values
1597 end
associate(type, name, opts = OPTS, &block) click to toggle source

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

:many_to_one

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

:one_to_many

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

:one_through_one

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

:one_to_one

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

:many_to_many

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

The following options can be supplied:

Multiple Types

:adder

Proc used to define the private add* method for doing the database work to associate the given object to the current object (*_to_many assocations). Set to nil to not define a add_* method for the association.

:after_add

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

:after_load

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

:after_remove

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

:after_set

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

:allow_eager

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

:allow_eager_graph

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

:allow_filtering_by

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

:before_add

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

:before_remove

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

:before_set

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

:cartesian_product_number

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

:class

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

:class_namespace

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

:clearer

Proc used to define the private remove_all* method for doing the database work to remove all objects associated to the current object (*_to_many assocations). Set to nil to not define a remove_all_* method for the association.

:clone

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

:conditions

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

:dataset

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

:distinct

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

:eager

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

:eager_block

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

:eager_graph

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

:eager_grapher

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

:eager_limit_strategy

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

:eager_loader

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

:eager_loader_key

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

:extend

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

:filter_limit_strategy

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

:graph_alias_base

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

:graph_block

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

:graph_conditions

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

:graph_join_type

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

:graph_only_conditions

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

:graph_order

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

:graph_select

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

:limit

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

:methods_module

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

:no_association_method

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

:no_dataset_method

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

:order

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

:order_eager_graph

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

:read_only

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

:reciprocal

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

:remover

Proc used to define the private remove* method for doing the database work to remove the association between the given object and the current object (*_to_many assocations). Set to nil to not define a remove_* method for the association.

:select

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

:setter

Proc used to define the private _*= method for doing the work to setup the assocation between the given object and the current object (*_to_one associations). Set to nil to not define a setter method for the association.

:subqueries_per_union

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

:validate

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

:many_to_one

:key

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

:key_column

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

:primary_key

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

:primary_key_method

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

:qualify

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

:one_to_many and :one_to_one

:key

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

:key_method

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

:primary_key

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

:primary_key_column

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

:raise_on_save_failure

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

:many_to_many and :one_through_one

:graph_join_table_block

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

:graph_join_table_conditions

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

:graph_join_table_join_type

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

:graph_join_table_only_conditions

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

:join_table

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

:join_table_block

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

:join_table_db

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

:left_key

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

:left_primary_key

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

:left_primary_key_column

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

:right_key

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

:right_primary_key

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

:right_primary_key_method

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

:uniq

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

     # File lib/sequel/model/associations.rb
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     remove_class_name = orig_opts[:class] && !orig_opts[:class_name]
1840     orig_opts = cloned_assoc[:orig_opts].merge(orig_opts)
1841     orig_opts.delete(:class_name) if remove_class_name
1842   end
1843 
1844   opts = Hash[default_association_options]
1845   if type_options = default_association_type_options[type]
1846     opts.merge!(type_options)
1847   end
1848   opts.merge!(orig_opts)
1849   opts.merge!(:type => type, :name => name, :cache=>({} if cache_associations), :model => self)
1850 
1851   opts[:block] = block if block
1852   opts[:instance_specific] = true if orig_opts[:dataset]
1853   if !opts.has_key?(:instance_specific) && (block || orig_opts[:block])
1854     # It's possible the association is instance specific, in that it depends on
1855     # values other than the foreign key value.  This needs to be checked for
1856     # in certain places to disable optimizations.
1857     opts[:instance_specific] = _association_instance_specific_default(name)
1858   end
1859   opts = assoc_class.new.merge!(opts)
1860 
1861   if opts[:clone] && !opts.cloneable?(cloned_assoc)
1862     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]})")
1863   end
1864 
1865   opts[:use_placeholder_loader] = !opts[:instance_specific] && !opts[:eager_graph]
1866   opts[:eager_block] = opts[:block] unless opts.include?(:eager_block)
1867   opts[:graph_join_type] ||= :left_outer
1868   opts[:order_eager_graph] = true unless opts.include?(:order_eager_graph)
1869   conds = opts[:conditions]
1870   opts[:graph_alias_base] ||= name
1871   opts[:graph_conditions] = conds if !opts.include?(:graph_conditions) and Sequel.condition_specifier?(conds)
1872   opts[:graph_conditions] = opts.fetch(:graph_conditions, []).to_a
1873   opts[:graph_select] = Array(opts[:graph_select]) if opts[:graph_select]
1874   [:before_add, :before_remove, :after_add, :after_remove, :after_load, :before_set, :after_set].each do |cb_type|
1875     opts[cb_type] = Array(opts[cb_type]) if opts[cb_type]
1876   end
1877 
1878   if opts[:extend]
1879     opts[:extend] = Array(opts[:extend])
1880     opts[:reverse_extend] = opts[:extend].reverse
1881   end
1882 
1883   late_binding_class_option(opts, opts.returns_array? ? singularize(name) : name)
1884   
1885   # Remove :class entry if it exists and is nil, to work with cached_fetch
1886   opts.delete(:class) unless opts[:class]
1887 
1888   def_association(opts)
1889       
1890   orig_opts.delete(:clone)
1891   opts[:orig_class] = orig_opts[:class] || orig_opts[:class_name]
1892   orig_opts.merge!(:class_name=>opts[:class_name], :class=>opts[:class], :block=>opts[:block])
1893   opts[:orig_opts] = orig_opts
1894   # don't add to association_reflections until we are sure there are no errors
1895   association_reflections[name] = opts
1896 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
1899 def association_reflection(name)
1900   association_reflections[name]
1901 end
associations() click to toggle source

Array of association name symbols

     # File lib/sequel/model/associations.rb
1904 def associations
1905   association_reflections.keys
1906 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
1909 def eager_load_results(opts, eo, &block)
1910   opts.eager_load_results(eo, &block)
1911 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
1928 def finalize_associations
1929   @association_reflections.each_value(&:finalize)
1930 end
freeze() click to toggle source

Freeze association related metadata when freezing model class.

Calls superclass method
     # File lib/sequel/model/associations.rb
1914 def freeze
1915   @association_reflections.freeze.each_value(&:freeze)
1916   @autoreloading_associations.freeze.each_value(&:freeze)
1917   @default_association_options.freeze
1918   @default_association_type_options.freeze
1919   @default_association_type_options.each_value(&:freeze)
1920 
1921   super
1922 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
1933 def many_to_many(name, opts=OPTS, &block)
1934   associate(:many_to_many, name, opts, &block)
1935 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
1938 def many_to_one(name, opts=OPTS, &block)
1939   associate(:many_to_one, name, opts, &block)
1940 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
1943 def one_through_one(name, opts=OPTS, &block)
1944   associate(:one_through_one, name, opts, &block)
1945 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
1948 def one_to_many(name, opts=OPTS, &block)
1949   associate(:one_to_many, name, opts, &block)
1950 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
1953 def one_to_one(name, opts=OPTS, &block)
1954   associate(:one_to_one, name, opts, &block)
1955 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
1964 def _association_instance_specific_default(_)
1965   true
1966 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
1970 def association_module(opts=OPTS)
1971   opts.fetch(:methods_module, overridable_methods_module)
1972 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
1977 def association_module_def(name, opts=OPTS, &block)
1978   mod = association_module(opts)
1979   mod.send(:define_method, name, &block)
1980   mod.send(:alias_method, name, name)
1981 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
1987 def association_module_delegate_def(name, opts, &block)
1988   mod = association_module(opts)
1989   mod.send(:define_method, name, &block)
1990   # :nocov:
1991   mod.send(:ruby2_keywords, name) if mod.respond_to?(:ruby2_keywords, true)
1992   # :nocov:
1993   mod.send(:alias_method, name, name)
1994 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
1997 def association_module_private_def(name, opts=OPTS, &block)
1998   association_module_def(name, opts, &block)
1999   association_module(opts).send(:private, name)
2000 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
2004 def def_association(opts)
2005   send(:"def_#{opts[:type]}", opts)
2006   def_association_instance_methods(opts)
2007 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
2017 def def_association_instance_methods(opts)
2018   # Always set the method names in the association reflection, even if they
2019   # are not used, for backwards compatibility.
2020   opts[:dataset_method] = :"#{opts[:name]}_dataset"
2021   if opts.returns_array?
2022     sname = singularize(opts[:name])
2023     opts[:_add_method] = :"_add_#{sname}"
2024     opts[:add_method] = :"add_#{sname}"
2025     opts[:_remove_method] = :"_remove_#{sname}"
2026     opts[:remove_method] = :"remove_#{sname}"
2027     opts[:_remove_all_method] = :"_remove_all_#{opts[:name]}"
2028     opts[:remove_all_method] = :"remove_all_#{opts[:name]}"
2029   else
2030     opts[:_setter_method] = :"_#{opts[:name]}="
2031     opts[:setter_method] = :"#{opts[:name]}="
2032   end
2033 
2034   association_module_def(opts.dataset_method, opts){_dataset(opts)} unless opts[:no_dataset_method]
2035   if opts[:block]
2036     opts[:block_method] = Plugins.def_sequel_method(association_module(opts), "#{opts[:name]}_block", 1, &opts[:block])
2037   end
2038   opts[:dataset_opt_arity] = opts[:dataset].arity == 0 ? 0 : 1
2039   opts[:dataset_opt_method] = Plugins.def_sequel_method(association_module(opts), "#{opts[:name]}_dataset_opt", opts[:dataset_opt_arity], &opts[:dataset])
2040   def_association_method(opts) unless opts[:no_association_method]
2041 
2042   return if opts[:read_only]
2043 
2044   if opts[:setter] && opts[:_setter]
2045     # This is backwards due to backwards compatibility
2046     association_module_private_def(opts[:_setter_method], opts, &opts[:setter])
2047     association_module_def(opts[:setter_method], opts, &opts[:_setter])
2048   end
2049 
2050   if adder = opts[:adder]
2051     association_module_private_def(opts[:_add_method], opts, &adder)
2052     association_module_delegate_def(opts[:add_method], opts){|o,*args| add_associated_object(opts, o, *args)}
2053   end
2054 
2055   if remover = opts[:remover]
2056     association_module_private_def(opts[:_remove_method], opts, &remover)
2057     association_module_delegate_def(opts[:remove_method], opts){|o,*args| remove_associated_object(opts, o, *args)}
2058   end
2059 
2060   if clearer = opts[:clearer]
2061     association_module_private_def(opts[:_remove_all_method], opts, &clearer)
2062     association_module_delegate_def(opts[:remove_all_method], opts){|*args| remove_all_associated_objects(opts, *args)}
2063   end
2064 end
def_association_method(opts) click to toggle source

Adds the association method to the association methods module.

     # File lib/sequel/model/associations.rb
2010 def def_association_method(opts)
2011   association_module_def(opts.association_method, opts) do |dynamic_opts=OPTS, &block|
2012     load_associated_objects(opts, dynamic_opts, &block)
2013   end
2014 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
2067 def def_many_to_many(opts)
2068   one_through_one = opts[:type] == :one_through_one
2069   left = (opts[:left_key] ||= opts.default_left_key)
2070   lcks = opts[:left_keys] = Array(left)
2071   right = (opts[:right_key] ||= opts.default_right_key)
2072   rcks = opts[:right_keys] = Array(right)
2073   left_pk = (opts[:left_primary_key] ||= self.primary_key)
2074   opts[:eager_loader_key] = left_pk unless opts.has_key?(:eager_loader_key)
2075   lcpks = opts[:left_primary_keys] = Array(left_pk)
2076   lpkc = opts[:left_primary_key_column] ||= left_pk
2077   lpkcs = opts[:left_primary_key_columns] ||= Array(lpkc)
2078   raise(Error, "mismatched number of left keys: #{lcks.inspect} vs #{lcpks.inspect}") unless lcks.length == lcpks.length
2079   if opts[:right_primary_key]
2080     rcpks = Array(opts[:right_primary_key])
2081     raise(Error, "mismatched number of right keys: #{rcks.inspect} vs #{rcpks.inspect}") unless rcks.length == rcpks.length
2082   end
2083   opts[:uses_left_composite_keys] = lcks.length > 1
2084   uses_rcks = opts[:uses_right_composite_keys] = rcks.length > 1
2085   opts[:cartesian_product_number] ||= one_through_one ? 0 : 1
2086   join_table = (opts[:join_table] ||= opts.default_join_table)
2087   opts[:left_key_alias] ||= opts.default_associated_key_alias
2088   opts[:graph_join_table_join_type] ||= opts[:graph_join_type]
2089   if opts[:uniq]
2090     opts[:after_load] ||= []
2091     opts[:after_load].unshift(:array_uniq!)
2092   end
2093   if join_table_db = opts[:join_table_db]
2094     opts[:use_placeholder_loader] = false
2095     opts[:allow_eager_graph] = false
2096     opts[:allow_filtering_by] = false
2097     opts[:eager_limit_strategy] = nil
2098     join_table_ds = join_table_db.from(join_table)
2099     opts[:dataset] ||= proc do |r|
2100       vals = join_table_ds.where(lcks.zip(lcpks.map{|k| get_column_value(k)})).select_map(right)
2101       ds = r.associated_dataset.where(opts.right_primary_key => vals)
2102       if uses_rcks
2103         vals.delete_if{|v| v.any?(&:nil?)}
2104       else
2105         vals.delete(nil)
2106       end
2107       ds = ds.clone(:no_results=>true) if vals.empty?
2108       ds
2109     end
2110     opts[:eager_loader] ||= proc do |eo|
2111       h = eo[:id_map]
2112       assign_singular = opts.assign_singular?
2113       rpk = opts.right_primary_key
2114       name = opts[:name]
2115 
2116       join_map = join_table_ds.where(left=>h.keys).select_hash_groups(right, left)
2117 
2118       if uses_rcks
2119         join_map.delete_if{|v,| v.any?(&:nil?)}
2120       else
2121         join_map.delete(nil)
2122       end
2123 
2124       eo = Hash[eo]
2125 
2126       if join_map.empty?
2127         eo[:no_results] = true
2128       else
2129         join_map.each_value do |vs|
2130           vs.replace(vs.flat_map{|v| h[v]})
2131           vs.uniq!
2132         end
2133 
2134         eo[:loader] = false
2135         eo[:right_keys] = join_map.keys
2136       end
2137 
2138       opts[:model].eager_load_results(opts, eo) do |assoc_record|
2139         rpkv = if uses_rcks
2140           assoc_record.values.values_at(*rpk)
2141         else
2142           assoc_record.values[rpk]
2143         end
2144 
2145         objects = join_map[rpkv]
2146 
2147         if assign_singular
2148           objects.each do |object|
2149             object.associations[name] ||= assoc_record
2150           end
2151         else
2152           objects.each do |object|
2153             object.associations[name].push(assoc_record)
2154           end
2155         end
2156       end
2157     end
2158   else
2159     opts[:dataset] ||= opts.association_dataset_proc
2160     opts[:eager_loader] ||= opts.method(:default_eager_loader)
2161   end
2162   
2163   join_type = opts[:graph_join_type]
2164   select = opts[:graph_select]
2165   use_only_conditions = opts.include?(:graph_only_conditions)
2166   only_conditions = opts[:graph_only_conditions]
2167   conditions = opts[:graph_conditions]
2168   graph_block = opts[:graph_block]
2169   graph_jt_conds = opts[:graph_join_table_conditions] = opts.fetch(:graph_join_table_conditions, []).to_a
2170   use_jt_only_conditions = opts.include?(:graph_join_table_only_conditions)
2171   jt_only_conditions = opts[:graph_join_table_only_conditions]
2172   jt_join_type = opts[:graph_join_table_join_type]
2173   jt_graph_block = opts[:graph_join_table_block]
2174   opts[:eager_grapher] ||= proc do |eo|
2175     ds = eo[:self]
2176     egls = eo[:limit_strategy]
2177     if egls && egls != :ruby
2178       associated_key_array = opts.associated_key_array
2179       orig_egds = egds = eager_graph_dataset(opts, eo)
2180       egds = egds.
2181         inner_join(join_table, rcks.zip(opts.right_primary_keys) + graph_jt_conds, :qualify=>:deep).
2182         select_all(egds.first_source).
2183         select_append(*associated_key_array)
2184       egds = opts.apply_eager_graph_limit_strategy(egls, egds)
2185       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)
2186     else
2187       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)
2188       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)
2189     end
2190   end
2191       
2192   return if opts[:read_only]
2193       
2194   if one_through_one
2195     unless opts.has_key?(:setter)
2196       opts[:setter] = proc do |o|
2197         h = {}
2198         lh = lcks.zip(lcpks.map{|k| get_column_value(k)})
2199         jtds = _join_table_dataset(opts).where(lh)
2200 
2201         checked_transaction do
2202           current = jtds.first
2203 
2204           if o
2205             new_values = []
2206             rcks.zip(opts.right_primary_key_methods).each{|k, pk| new_values << (h[k] = o.get_column_value(pk))}
2207           end
2208 
2209           if current
2210             current_values = rcks.map{|k| current[k]}
2211             jtds = jtds.where(rcks.zip(current_values))
2212             if o
2213               if current_values != new_values
2214                 jtds.update(h)
2215               end
2216             else
2217               jtds.delete
2218             end
2219           elsif o
2220             lh.each{|k,v| h[k] = v}
2221             jtds.insert(h)
2222           end
2223         end
2224       end
2225     end
2226     if opts.fetch(:setter, true)
2227       opts[:_setter] = proc{|o| set_one_through_one_associated_object(opts, o)}
2228     end
2229   else 
2230     unless opts.has_key?(:adder)
2231       opts[:adder] = proc do |o|
2232         h = {}
2233         lcks.zip(lcpks).each{|k, pk| h[k] = get_column_value(pk)}
2234         rcks.zip(opts.right_primary_key_methods).each{|k, pk| h[k] = o.get_column_value(pk)}
2235         _join_table_dataset(opts).insert(h)
2236       end
2237     end
2238 
2239     unless opts.has_key?(:remover)
2240       opts[:remover] = proc do |o|
2241         _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
2242       end
2243     end
2244 
2245     unless opts.has_key?(:clearer)
2246       opts[:clearer] = proc do
2247         _join_table_dataset(opts).where(lcks.zip(lcpks.map{|k| get_column_value(k)})).delete
2248       end
2249     end
2250   end
2251 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
2254 def def_many_to_one(opts)
2255   name = opts[:name]
2256   opts[:key] = opts.default_key unless opts.has_key?(:key)
2257   key = opts[:key]
2258   opts[:eager_loader_key] = key unless opts.has_key?(:eager_loader_key)
2259   cks = opts[:graph_keys] = opts[:keys] = Array(key)
2260   opts[:key_column] ||= key
2261   opts[:graph_keys] = opts[:key_columns] = Array(opts[:key_column])
2262   opts[:qualified_key] = opts.qualify_cur(key)
2263   if opts[:primary_key]
2264     cpks = Array(opts[:primary_key])
2265     raise(Error, "mismatched number of keys: #{cks.inspect} vs #{cpks.inspect}") unless cks.length == cpks.length
2266   end
2267   uses_cks = opts[:uses_composite_keys] = cks.length > 1
2268   opts[:cartesian_product_number] ||= 0
2269 
2270   if !opts.has_key?(:many_to_one_pk_lookup) &&
2271      (opts[:dataset] || opts[:conditions] || opts[:block] || opts[:select] ||
2272       (opts.has_key?(:key) && opts[:key] == nil))
2273     opts[:many_to_one_pk_lookup] = false
2274   end
2275   auto_assocs = @autoreloading_associations
2276   cks.each do |k|
2277     (auto_assocs[k] ||= []) << name
2278   end
2279 
2280   opts[:dataset] ||= opts.association_dataset_proc
2281   opts[:eager_loader] ||= proc do |eo|
2282     h = eo[:id_map]
2283     pk_meths = opts.primary_key_methods
2284 
2285     eager_load_results(opts, eo) do |assoc_record|
2286       hash_key = uses_cks ? pk_meths.map{|k| assoc_record.get_column_value(k)} : assoc_record.get_column_value(opts.primary_key_method)
2287       h[hash_key].each{|object| object.associations[name] = assoc_record}
2288     end
2289   end
2290       
2291   join_type = opts[:graph_join_type]
2292   select = opts[:graph_select]
2293   use_only_conditions = opts.include?(:graph_only_conditions)
2294   only_conditions = opts[:graph_only_conditions]
2295   conditions = opts[:graph_conditions]
2296   graph_block = opts[:graph_block]
2297   graph_cks = opts[:graph_keys]
2298   opts[:eager_grapher] ||= proc do |eo|
2299     ds = eo[:self]
2300     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)
2301   end
2302       
2303   return if opts[:read_only]
2304       
2305   unless opts.has_key?(:setter)
2306     opts[:setter] = proc{|o| cks.zip(opts.primary_key_methods).each{|k, pk| set_column_value(:"#{k}=", (o.get_column_value(pk) if o))}}
2307   end
2308   if opts.fetch(:setter, true)
2309     opts[:_setter] = proc{|o| set_associated_object(opts, o)}
2310   end
2311 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
2435 def def_one_through_one(opts)
2436   def_many_to_many(opts)
2437 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
2314 def def_one_to_many(opts)
2315   one_to_one = opts[:type] == :one_to_one
2316   name = opts[:name]
2317   key = (opts[:key] ||= opts.default_key)
2318   km = opts[:key_method] ||= opts[:key]
2319   cks = opts[:keys] = Array(key)
2320   opts[:key_methods] = Array(opts[:key_method])
2321   primary_key = (opts[:primary_key] ||= self.primary_key)
2322   opts[:eager_loader_key] = primary_key unless opts.has_key?(:eager_loader_key)
2323   cpks = opts[:primary_keys] = Array(primary_key)
2324   pkc = opts[:primary_key_column] ||= primary_key
2325   pkcs = opts[:primary_key_columns] ||= Array(pkc)
2326   raise(Error, "mismatched number of keys: #{cks.inspect} vs #{cpks.inspect}") unless cks.length == cpks.length
2327   uses_cks = opts[:uses_composite_keys] = cks.length > 1
2328   opts[:dataset] ||= opts.association_dataset_proc
2329   opts[:eager_loader] ||= proc do |eo|
2330     h = eo[:id_map]
2331     reciprocal = opts.reciprocal
2332     assign_singular = opts.assign_singular?
2333     delete_rn = opts.delete_row_number_column
2334 
2335     eager_load_results(opts, eo) do |assoc_record|
2336       assoc_record.values.delete(delete_rn) if delete_rn
2337       hash_key = uses_cks ? km.map{|k| assoc_record.get_column_value(k)} : assoc_record.get_column_value(km)
2338       objects = h[hash_key]
2339       if assign_singular
2340         objects.each do |object| 
2341           unless object.associations[name]
2342             object.associations[name] = assoc_record
2343             assoc_record.associations[reciprocal] = object if reciprocal
2344           end
2345         end
2346       else
2347         objects.each do |object| 
2348           object.associations[name].push(assoc_record)
2349           assoc_record.associations[reciprocal] = object if reciprocal
2350         end
2351       end
2352     end
2353   end
2354   
2355   join_type = opts[:graph_join_type]
2356   select = opts[:graph_select]
2357   use_only_conditions = opts.include?(:graph_only_conditions)
2358   only_conditions = opts[:graph_only_conditions]
2359   conditions = opts[:graph_conditions]
2360   opts[:cartesian_product_number] ||= one_to_one ? 0 : 1
2361   graph_block = opts[:graph_block]
2362   opts[:eager_grapher] ||= proc do |eo|
2363     ds = eo[:self]
2364     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)
2365     # We only load reciprocals for one_to_many associations, as other reciprocals don't make sense
2366     ds.opts[:eager_graph][:reciprocals][eo[:table_alias]] = opts.reciprocal
2367     ds
2368   end
2369       
2370   return if opts[:read_only]
2371 
2372   save_opts = {:validate=>opts[:validate]}
2373   ck_nil_hash ={}
2374   cks.each{|k| ck_nil_hash[k] = nil}
2375 
2376   if one_to_one
2377     unless opts.has_key?(:setter)
2378       opts[:setter] = proc do |o|
2379         up_ds = _apply_association_options(opts, opts.associated_dataset.where(cks.zip(cpks.map{|k| get_column_value(k)})))
2380 
2381         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)))
2382           if old = up_ds.first
2383             cks.each{|k| old.set_column_value(:"#{k}=", nil)}
2384           end
2385           save_old = true
2386         end
2387 
2388         if o
2389           if !o.new? && !save_old
2390             up_ds = up_ds.exclude(o.pk_hash)
2391           end
2392           cks.zip(cpks).each{|k, pk| o.set_column_value(:"#{k}=", get_column_value(pk))}
2393         end
2394 
2395         checked_transaction do
2396           if save_old
2397             old.save(save_opts) || raise(Sequel::Error, "invalid previously associated object, cannot save") if old
2398           else
2399             up_ds.skip_limit_check.update(ck_nil_hash)
2400           end
2401 
2402           o.save(save_opts) || raise(Sequel::Error, "invalid associated object, cannot save") if o
2403         end
2404       end
2405     end
2406     if opts.fetch(:setter, true)
2407       opts[:_setter] = proc{|o| set_one_to_one_associated_object(opts, o)}
2408     end
2409   else 
2410     save_opts[:raise_on_failure] = opts[:raise_on_save_failure] != false
2411 
2412     unless opts.has_key?(:adder)
2413       opts[:adder] = proc do |o|
2414         cks.zip(cpks).each{|k, pk| o.set_column_value(:"#{k}=", get_column_value(pk))}
2415         o.save(save_opts)
2416       end
2417     end
2418     
2419     unless opts.has_key?(:remover)
2420       opts[:remover] = proc do |o|
2421         cks.each{|k| o.set_column_value(:"#{k}=", nil)}
2422         o.save(save_opts)
2423       end
2424     end
2425 
2426     unless opts.has_key?(:clearer)
2427       opts[:clearer] = proc do
2428         _apply_association_options(opts, opts.associated_dataset.where(cks.zip(cpks.map{|k| get_column_value(k)}))).update(ck_nil_hash)
2429       end
2430     end
2431   end
2432 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
2440 def def_one_to_one(opts)
2441   def_one_to_many(opts)
2442 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
2445 def eager_graph_dataset(opts, eager_options)
2446   ds = opts.associated_class.dataset
2447   if cb = eager_options[:callback]
2448     ds = cb.call(ds)
2449   end
2450   ds
2451 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
2455 def reload_db_schema?
2456   !@cache_associations
2457 end