class Sequel::Model::Associations::ManyToManyAssociationReflection

Constants

FINALIZE_SETTINGS

Public Instance Methods

associated_key_alias() click to toggle source

The alias to use for the associated key when eagerly loading

     # File lib/sequel/model/associations.rb
1241 def associated_key_alias
1242   self[:left_key_alias]
1243 end
associated_key_array() click to toggle source

Array of associated keys used when eagerly loading.

     # File lib/sequel/model/associations.rb
1246 def associated_key_array
1247   cached_fetch(:associated_key_array) do
1248     if self[:uses_left_composite_keys]
1249       associated_key_alias.zip(predicate_keys).map{|a, k| SQL::AliasedExpression.new(k, a)}
1250     else
1251       [SQL::AliasedExpression.new(predicate_key, associated_key_alias)]
1252     end
1253   end
1254 end
associated_key_column() click to toggle source

The column to use for the associated key when eagerly loading

     # File lib/sequel/model/associations.rb
1257 def associated_key_column
1258   self[:left_key]
1259 end
associated_key_table()
Alias for: join_table_alias
associated_object_keys() click to toggle source

Alias of right_primary_keys

     # File lib/sequel/model/associations.rb
1262 def associated_object_keys
1263   right_primary_keys
1264 end
can_have_associated_objects?(obj) click to toggle source

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

     # File lib/sequel/model/associations.rb
1268 def can_have_associated_objects?(obj)
1269   !self[:left_primary_keys].any?{|k| obj.get_column_value(k).nil?}
1270 end
cloneable?(ref) click to toggle source

one_through_one and many_to_many associations can be clones

     # File lib/sequel/model/associations.rb
1273 def cloneable?(ref)
1274   ref[:type] == :many_to_many || ref[:type] == :one_through_one
1275 end
default_associated_key_alias() click to toggle source

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

     # File lib/sequel/model/associations.rb
1279 def default_associated_key_alias
1280   self[:uses_left_composite_keys] ? (0...self[:left_keys].length).map{|i| :"x_foreign_key_#{i}_x"} : :x_foreign_key_x
1281 end
default_eager_loader(eo) click to toggle source

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.

     # File lib/sequel/model/associations.rb
1285 def default_eager_loader(eo)
1286   h = eo[:id_map]
1287   assign_singular = assign_singular?
1288   delete_rn = delete_row_number_column
1289   uses_lcks = self[:uses_left_composite_keys]
1290   left_key_alias = self[:left_key_alias]
1291   name = self[:name]
1292 
1293   self[:model].eager_load_results(self, eo) do |assoc_record|
1294     assoc_record.values.delete(delete_rn) if delete_rn
1295     hash_key = if uses_lcks
1296       left_key_alias.map{|k| assoc_record.values.delete(k)}
1297     else
1298       assoc_record.values.delete(left_key_alias)
1299     end
1300 
1301     objects = h[hash_key]
1302 
1303     if assign_singular
1304       objects.each do |object| 
1305         object.associations[name] ||= assoc_record
1306       end
1307     else
1308       objects.each do |object|
1309         object.associations[name].push(assoc_record)
1310       end
1311     end
1312   end
1313 end
default_join_table() click to toggle source

Default name symbol for the join table.

     # File lib/sequel/model/associations.rb
1316 def default_join_table
1317   [self[:class_name], self[:model].name].map{|i| underscore(pluralize(demodulize(i)))}.sort.join('_').to_sym
1318 end
default_left_key() click to toggle source

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

     # File lib/sequel/model/associations.rb
1322 def default_left_key
1323   :"#{underscore(demodulize(self[:model].name))}_id"
1324 end
default_right_key() click to toggle source

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).

     # File lib/sequel/model/associations.rb
1328 def default_right_key
1329   :"#{singularize(self[:name])}_id"
1330 end
eager_loading_use_associated_key?() click to toggle source

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

     # File lib/sequel/model/associations.rb
1361 def eager_loading_use_associated_key?
1362   !separate_query_per_table?
1363 end
finalize_settings() click to toggle source
     # File lib/sequel/model/associations.rb
1344 def finalize_settings
1345   FINALIZE_SETTINGS
1346 end
join_table_alias() click to toggle source

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

     # File lib/sequel/model/associations.rb
1373 def join_table_alias
1374   cached_fetch(:join_table_alias) do
1375     s, a = split_join_table_alias
1376     a || s
1377   end
1378 end
Also aliased as: associated_key_table
join_table_source() click to toggle source

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

     # File lib/sequel/model/associations.rb
1367 def join_table_source
1368   cached_fetch(:join_table_source){split_join_table_alias[0]}
1369 end
need_associated_primary_key?() click to toggle source

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

     # File lib/sequel/model/associations.rb
1383 def need_associated_primary_key?
1384   true
1385 end
predicate_key() click to toggle source

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.

     # File lib/sequel/model/associations.rb
1350 def predicate_key
1351   cached_fetch(:predicate_key){qualify(join_table_alias, self[:left_key])}
1352 end
Also aliased as: qualified_left_key
qualified_left_key()
Alias for: predicate_key
qualified_right_key() click to toggle source

The right key qualified by the join table.

     # File lib/sequel/model/associations.rb
1356 def qualified_right_key
1357   cached_fetch(:qualified_right_key){qualify(join_table_alias, self[:right_key])}
1358 end
qualified_right_primary_key() click to toggle source

right_primary_key qualified by the associated table

     # File lib/sequel/model/associations.rb
1388 def qualified_right_primary_key
1389   cached_fetch(:qualified_right_primary_key){qualify_assoc(right_primary_key)}
1390 end
right_primary_key() click to toggle source

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

     # File lib/sequel/model/associations.rb
1393 def right_primary_key
1394   cached_fetch(:right_primary_key){associated_class.primary_key || raise(Error, "no primary key specified for #{associated_class.inspect}")}
1395 end
right_primary_key_method() click to toggle source

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

     # File lib/sequel/model/associations.rb
1404 def right_primary_key_method
1405   cached_fetch(:right_primary_key_method){right_primary_key}
1406 end
right_primary_key_methods() click to toggle source

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

     # File lib/sequel/model/associations.rb
1410 def right_primary_key_methods
1411   cached_fetch(:right_primary_key_methods){Array(right_primary_key_method)}
1412 end
right_primary_keys() click to toggle source

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

     # File lib/sequel/model/associations.rb
1398 def right_primary_keys
1399   cached_fetch(:right_primary_keys){Array(right_primary_key)}
1400 end
select() click to toggle source

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

     # File lib/sequel/model/associations.rb
1415 def select
1416   cached_fetch(:select){default_select}
1417 end
separate_query_per_table?() click to toggle source

Whether a separate query should be used for the join table.

     # File lib/sequel/model/associations.rb
1420 def separate_query_per_table?
1421   self[:join_table_db]
1422 end

Private Instance Methods

_associated_dataset() click to toggle source

Join to the the join table, unless using a separate query per table.

     # File lib/sequel/model/associations.rb
1427 def _associated_dataset
1428   if separate_query_per_table?
1429     super
1430   else
1431     super.inner_join(self[:join_table], self[:right_keys].zip(right_primary_keys), :qualify=>:deep)
1432   end
1433 end
default_select() click to toggle source

The default selection for associations that require joins. These do not use the default model selection unless all entries in the select are explicitly qualified identifiers, as other it can include unqualified columns which would be made ambiguous by joining.

     # File lib/sequel/model/associations.rb
1448 def default_select
1449   if (sel = associated_class.dataset.opts[:select]) && sel.all?{|c| selection_is_qualified?(c)}
1450     sel
1451   else
1452     Sequel::SQL::ColumnAll.new(associated_class.table_name)
1453   end
1454 end
eager_loading_set_predicate_condition(ds, eo) click to toggle source

Use the right_keys from the eager loading options if using a separate query per table.

     # File lib/sequel/model/associations.rb
1437 def eager_loading_set_predicate_condition(ds, eo)
1438   if separate_query_per_table?
1439     ds.where(right_primary_key=>eo[:right_keys])
1440   else
1441     super
1442   end
1443 end
filter_by_associations_conditions_associated_keys() click to toggle source
     # File lib/sequel/model/associations.rb
1456 def filter_by_associations_conditions_associated_keys
1457   qualify(join_table_alias, self[:left_keys])
1458 end
filter_by_associations_conditions_key() click to toggle source
     # File lib/sequel/model/associations.rb
1460 def filter_by_associations_conditions_key
1461   qualify(self[:model].table_name, self[:left_primary_key_column])
1462 end
filter_by_associations_limit_alias_key() click to toggle source
     # File lib/sequel/model/associations.rb
1464 def filter_by_associations_limit_alias_key
1465   aliaz = 'a'
1466   filter_by_associations_limit_key.map{|c| c.as(Sequel.identifier(aliaz = aliaz.next))}
1467 end
filter_by_associations_limit_aliases() click to toggle source
     # File lib/sequel/model/associations.rb
1469 def filter_by_associations_limit_aliases
1470   filter_by_associations_limit_alias_key.map(&:alias)
1471 end
filter_by_associations_limit_key() click to toggle source
     # File lib/sequel/model/associations.rb
1473 def filter_by_associations_limit_key
1474   qualify(join_table_alias, self[:left_keys]) + Array(qualify(associated_class.table_name, associated_class.primary_key))
1475 end
predicate_key_methods() click to toggle source
     # File lib/sequel/model/associations.rb
1477 def predicate_key_methods
1478   self[:left_primary_keys]
1479 end
reciprocal_association?(assoc_reflect) click to toggle source
     # File lib/sequel/model/associations.rb
1481 def reciprocal_association?(assoc_reflect)
1482   super && assoc_reflect[:left_keys] == self[:right_keys] &&
1483     assoc_reflect[:right_keys] == self[:left_keys] &&
1484     assoc_reflect[:join_table] == self[:join_table] &&
1485     right_primary_keys == assoc_reflect[:left_primary_key_columns] &&
1486     self[:left_primary_key_columns] == assoc_reflect.right_primary_keys
1487 end
reciprocal_type() click to toggle source
     # File lib/sequel/model/associations.rb
1489 def reciprocal_type
1490   :many_to_many
1491 end
selection_is_qualified?(c) click to toggle source

Whether the given expression represents a qualified identifier. Used to determine if it is OK to use directly when joining.

     # File lib/sequel/model/associations.rb
1495 def selection_is_qualified?(c)
1496   case c
1497   when Symbol
1498     Sequel.split_symbol(c)[0]
1499   when Sequel::SQL::QualifiedIdentifier
1500     true
1501   when Sequel::SQL::AliasedExpression
1502     selection_is_qualified?(c.expression)
1503   else
1504     false
1505   end
1506 end
split_join_table_alias() click to toggle source

Split the join table into source and alias parts.

     # File lib/sequel/model/associations.rb
1509 def split_join_table_alias
1510   associated_class.dataset.split_alias(self[:join_table])
1511 end