def construct_joins(custom_joins = nil)
polymorphic_join = nil
if @reflection.source_reflection.macro == :belongs_to
reflection_primary_key = @reflection.klass.primary_key
source_primary_key = @reflection.source_reflection.primary_key_name
if @reflection.options[:source_type]
polymorphic_join = "AND %s.%s = %s" % [
@reflection.through_reflection.quoted_table_name, "#{@reflection.source_reflection.options[:foreign_type]}",
@owner.class.quote_value(@reflection.options[:source_type])
]
end
else
reflection_primary_key = @reflection.source_reflection.primary_key_name
source_primary_key = @reflection.through_reflection.klass.primary_key
if @reflection.source_reflection.options[:as]
polymorphic_join = "AND %s.%s = %s" % [
@reflection.quoted_table_name, "#{@reflection.source_reflection.options[:as]}_type",
@owner.class.quote_value(@reflection.through_reflection.klass.name)
]
end
end
"INNER JOIN %s ON %s.%s = %s.%s %s #{@reflection.options[:joins]} #{custom_joins}" % [
@reflection.through_reflection.quoted_table_name,
@reflection.quoted_table_name, reflection_primary_key,
@reflection.through_reflection.quoted_table_name, source_primary_key,
polymorphic_join
]
end