Class: Sequel::Model::Associations::ManyToManyAssociationReflection

Inherits:
AssociationReflection show all
Defined in:
lib/sequel/model/associations.rb

Constant Summary

Constants inherited from AssociationReflection

AssociationReflection::ASSOCIATION_DATASET_PROC

Constants included from Inflections

Inflections::CAMELIZE_CONVERT_REGEXP, Inflections::CAMELIZE_MODULE_REGEXP, Inflections::DASH, Inflections::DEMODULIZE_CONVERT_REGEXP, Inflections::EMPTY_STRING, Inflections::SLASH, Inflections::UNDERSCORE, Inflections::UNDERSCORE_CONVERT_REGEXP1, Inflections::UNDERSCORE_CONVERT_REGEXP2, Inflections::UNDERSCORE_CONVERT_REPLACE, Inflections::UNDERSCORE_MODULE_REGEXP, Inflections::VALID_CONSTANT_NAME_REGEXP

Instance Method Summary collapse

Methods inherited from AssociationReflection

#_add_method, #_remove_all_method, #_remove_method, #_setter_method, #add_method, #apply_dataset_changes, #apply_distinct_on_eager_limit_strategy, #apply_eager_dataset_changes, #apply_eager_graph_limit_strategy, #apply_eager_limit_strategy, #apply_ruby_eager_limit_strategy, #apply_window_function_eager_limit_strategy, #assign_singular?, #associated_class, #associated_dataset, #association_dataset_for, #association_dataset_proc, #association_method, #dataset_method, #dataset_need_primary_key?, #delete_row_number_column, #eager_graph_lazy_dataset?, #eager_graph_limit_strategy, #eager_limit_strategy, #eager_load_results, #eager_loader_key, #eager_loading_predicate_key, #filter_by_associations_add_conditions?, #filter_by_associations_conditions_expression, #handle_silent_modification_failure?, #initialize_association_cache, #limit_and_offset, #placeholder_loader, #predicate_key_values, #predicate_keys, #qualify, #qualify_assoc, #qualify_cur, #reciprocal, #reciprocal_array?, #remove_all_method, #remove_before_destroy?, #remove_method, #remove_should_check_existing?, #returns_array?, #set_reciprocal_to_self?, #setter_method, #slice_range

Methods included from Inflections

clear, irregular, plural, singular, uncountable

Methods inherited from Hash

#&, #case, #hstore, #pg_json, #pg_jsonb, #sql_expr, #sql_negate, #sql_or, #|, #~

Instance Method Details

#associated_key_alias ⇒ Object

The alias to use for the associated key when eagerly loading



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# File 'lib/sequel/model/associations.rb', line 1101

def associated_key_alias
  self[:left_key_alias]
end

#associated_key_array ⇒ Object

Array of associated keys used when eagerly loading.



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# File 'lib/sequel/model/associations.rb', line 1106

def associated_key_array
  cached_fetch(:associated_key_array) do
    if self[:uses_left_composite_keys]
      associated_key_alias.zip(predicate_keys).map{|a, k| SQL::AliasedExpression.new(k, a)}
    else
      [SQL::AliasedExpression.new(predicate_key, associated_key_alias)]
    end
  end
end

#associated_key_column ⇒ Object

The column to use for the associated key when eagerly loading



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# File 'lib/sequel/model/associations.rb', line 1117

def associated_key_column
  self[:left_key]
end

#associated_object_keys ⇒ Object

Alias of right_primary_keys



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# File 'lib/sequel/model/associations.rb', line 1122

def associated_object_keys
  right_primary_keys
end

#can_have_associated_objects?(obj) ⇒ Boolean

many_to_many associations can only have associated objects if none of the :left_primary_keys options have a nil value.

Returns:

  • (Boolean) 


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# File 'lib/sequel/model/associations.rb', line 1128

def can_have_associated_objects?(obj)
  !self[:left_primary_keys].any?{|k| obj.get_column_value(k).nil?}
end

#cloneable?(ref) ⇒ Boolean

one_through_one and many_to_many associations can be clones

Returns:

  • (Boolean) 


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# File 'lib/sequel/model/associations.rb', line 1133

def cloneable?(ref)
  ref[:type] == :many_to_many || ref[:type] == :one_through_one
end

#default_associated_key_alias ⇒ Object

The default associated key alias(es) to use when eager loading associations via eager.



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# File 'lib/sequel/model/associations.rb', line 1139

def default_associated_key_alias
  self[:uses_left_composite_keys] ? (0...self[:left_keys].length).map{|i| :"x_foreign_key_#{i}_x"} : :x_foreign_key_x
end

#default_eager_loader(eo) ⇒ Object

The default eager loader used if the user doesn’t override it. Extracted to a method so the code can be shared with the many_through_many plugin.



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# File 'lib/sequel/model/associations.rb', line 1145

def default_eager_loader(eo)
  h = eo[:id_map]
  assign_singular = assign_singular?
  delete_rn = delete_row_number_column
  uses_lcks = self[:uses_left_composite_keys]
  left_key_alias = self[:left_key_alias]
  name = self[:name]

  self[:model].eager_load_results(self, eo) do |assoc_record|
    assoc_record.values.delete(delete_rn) if delete_rn
    hash_key = if uses_lcks
      left_key_alias.map{|k| assoc_record.values.delete(k)}
    else
      assoc_record.values.delete(left_key_alias)
    end
    next unless objects = h[hash_key]
    if assign_singular
      objects.each do |object| 
        object.associations[name] ||= assoc_record
      end
    else
      objects.each do |object|
        object.associations[name].push(assoc_record)
      end
    end
  end
end

#default_join_table ⇒ Object

Default name symbol for the join table.



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# File 'lib/sequel/model/associations.rb', line 1174

def default_join_table
  [self[:class_name], self[:model].name].map{|i| underscore(pluralize(demodulize(i)))}.sort.join('_').to_sym
end

#default_left_key ⇒ Object

Default foreign key name symbol for key in join table that points to current table’s primary key (or :left_primary_key column).



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# File 'lib/sequel/model/associations.rb', line 1180

def default_left_key
  :"#{underscore(demodulize(self[:model].name))}_id"
end

#default_right_key ⇒ Object

Default foreign key name symbol for foreign key in join table that points to the association’s table’s primary key (or :right_primary_key column).



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# File 'lib/sequel/model/associations.rb', line 1186

def default_right_key
  :"#{singularize(self[:name])}_id"
end

#eager_loading_use_associated_key? ⇒ Boolean

many_to_many associations need to select a key in an associated table to eagerly load

Returns:

  • (Boolean) 


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# File 'lib/sequel/model/associations.rb', line 1203

def eager_loading_use_associated_key?
  true
end

#join_table_alias ⇒ Object Also known as: associated_key_table

The join table itself, unless it is aliased, in which case this is the alias.



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# File 'lib/sequel/model/associations.rb', line 1215

def join_table_alias
  cached_fetch(:join_table_alias) do
    s, a = split_join_table_alias
    a || s
  end
end

#join_table_source ⇒ Object

The source of the join table. This is the join table itself, unless it is aliased, in which case it is the unaliased part.



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# File 'lib/sequel/model/associations.rb', line 1209

def join_table_source
  cached_fetch(:join_table_source){split_join_table_alias[0]}
end

#need_associated_primary_key? ⇒ Boolean

Whether the associated object needs a primary key to be added/removed, true for many_to_many associations.

Returns:

  • (Boolean) 


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# File 'lib/sequel/model/associations.rb', line 1225

def need_associated_primary_key?
  true
end

#predicate_key ⇒ Object Also known as: qualified_left_key

The hash key to use for the eager loading predicate (left side of IN (1, 2, 3)). The left key qualified by the join table.



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# File 'lib/sequel/model/associations.rb', line 1192

def predicate_key
  cached_fetch(:predicate_key){qualify(join_table_alias, self[:left_key])}
end

#qualified_right_key ⇒ Object

The right key qualified by the join table.



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# File 'lib/sequel/model/associations.rb', line 1198

def qualified_right_key
  cached_fetch(:qualified_right_key){qualify(join_table_alias, self[:right_key])}
end

#qualified_right_primary_key ⇒ Object

#right_primary_key qualified by the associated table



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# File 'lib/sequel/model/associations.rb', line 1230

def qualified_right_primary_key
  cached_fetch(:qualified_right_primary_key){qualify_assoc(right_primary_key)}
end

#right_primary_key ⇒ Object

The primary key column(s) to use in the associated table (can be symbol or array).



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# File 'lib/sequel/model/associations.rb', line 1235

def right_primary_key
  cached_fetch(:right_primary_key){associated_class.primary_key || raise(Error, "no primary key specified for #{associated_class.inspect}")}
end

#right_primary_key_method ⇒ Object

The method symbol or array of method symbols to call on the associated objects to get the foreign key values for the join table.



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# File 'lib/sequel/model/associations.rb', line 1246

def right_primary_key_method
  cached_fetch(:right_primary_key_method){right_primary_key}
end

#right_primary_key_methods ⇒ Object

The array of method symbols to call on the associated objects to get the foreign key values for the join table.



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# File 'lib/sequel/model/associations.rb', line 1252

def right_primary_key_methods
  cached_fetch(:right_primary_key_methods){Array(right_primary_key_method)}
end

#right_primary_keys ⇒ Object

The primary key columns to use in the associated table (always array).



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# File 'lib/sequel/model/associations.rb', line 1240

def right_primary_keys
  cached_fetch(:right_primary_keys){Array(right_primary_key)}
end

#select ⇒ Object

The columns to select when loading the association, associated_class.table_name.* by default.



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# File 'lib/sequel/model/associations.rb', line 1257

def select
  cached_fetch(:select){default_select}
end