Class: ActiveRecord::Associations::JoinDependency::JoinAssociation
- Inherits:
-
JoinPart
- Object
- JoinPart
- ActiveRecord::Associations::JoinDependency::JoinAssociation
- Defined in:
- lib/active_record/associations/join_dependency/join_association.rb
Overview
:nodoc:
Defined Under Namespace
Classes: JoinInformation
Instance Attribute Summary collapse
-
#reflection ⇒ Object
readonly
The reflection of the association represented.
-
#tables ⇒ Object
Returns the value of attribute tables.
Attributes inherited from JoinPart
Instance Method Summary collapse
- #aliased_table_name ⇒ Object
-
#build_constraint(klass, table, key, foreign_table, foreign_key) ⇒ Object
Builds equality condition.
-
#initialize(reflection, children) ⇒ JoinAssociation
constructor
A new instance of JoinAssociation.
- #join_constraints(foreign_table, foreign_klass, join_type, tables, chain) ⇒ Object
- #match?(other) ⇒ Boolean
- #table ⇒ Object
Methods inherited from JoinPart
#each, #extract_record, #instantiate, #name
Constructor Details
#initialize(reflection, children) ⇒ JoinAssociation
Returns a new instance of JoinAssociation.
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# File 'lib/active_record/associations/join_dependency/join_association.rb', line 12 def initialize(reflection, children) super(reflection.klass, children) @reflection = reflection @tables = nil end |
Instance Attribute Details
#reflection ⇒ Object (readonly)
The reflection of the association represented
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# File 'lib/active_record/associations/join_dependency/join_association.rb', line 8 def reflection @reflection end |
#tables ⇒ Object
Returns the value of attribute tables.
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# File 'lib/active_record/associations/join_dependency/join_association.rb', line 10 def tables @tables end |
Instance Method Details
#aliased_table_name ⇒ Object
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# File 'lib/active_record/associations/join_dependency/join_association.rb', line 99 def aliased_table_name table.table_alias || table.name end |
#build_constraint(klass, table, key, foreign_table, foreign_key) ⇒ Object
Builds equality condition.
Example:
class Physician < ActiveRecord::Base
has_many :appointments
end
If I execute `Physician.joins(:appointments).to_a` then
klass # => Physician
table # => #<Arel::Table @name="appointments" ...>
key # => physician_id
foreign_table # => #<Arel::Table @name="physicians" ...>
foreign_key # => id
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# File 'lib/active_record/associations/join_dependency/join_association.rb', line 82 def build_constraint(klass, table, key, foreign_table, foreign_key) constraint = table[key].eq(foreign_table[foreign_key]) if klass.finder_needs_type_condition? constraint = table.create_and([ constraint, klass.send(:type_condition, table) ]) end constraint end |
#join_constraints(foreign_table, foreign_klass, join_type, tables, chain) ⇒ Object
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# File 'lib/active_record/associations/join_dependency/join_association.rb', line 26 def join_constraints(foreign_table, foreign_klass, join_type, tables, chain) joins = [] binds = [] tables = tables.reverse # The chain starts with the target table, but we want to end with it here (makes # more sense in this context), so we reverse chain.reverse_each do |reflection| table = tables.shift klass = reflection.klass join_keys = reflection.join_keys key = join_keys.key foreign_key = join_keys.foreign_key constraint = build_constraint(klass, table, key, foreign_table, foreign_key) rel = reflection.join_scope(table) if rel && !rel.arel.constraints.empty? binds += rel.bound_attributes constraint = constraint.and rel.arel.constraints end if reflection.type value = foreign_klass.base_class.name column = klass.columns_hash[reflection.type.to_s] binds << Relation::QueryAttribute.new(column.name, value, klass.type_for_attribute(column.name)) constraint = constraint.and klass.arel_attribute(reflection.type, table).eq(Arel::Nodes::BindParam.new) end joins << table.create_join(table, table.create_on(constraint), join_type) # The current table in this iteration becomes the foreign table in the next foreign_table, foreign_klass = table, klass end JoinInformation.new joins, binds end |
#match?(other) ⇒ Boolean
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# File 'lib/active_record/associations/join_dependency/join_association.rb', line 19 def match?(other) return true if self == other super && reflection == other.reflection end |
#table ⇒ Object
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# File 'lib/active_record/associations/join_dependency/join_association.rb', line 95 def table tables.first end |