module ActiveRecord
# = Active Record Has And Belongs To Many Association
module Associations
class HasAndBelongsToManyAssociation < AssociationCollection #:nodoc:
def create(attributes = {})
create_record(attributes) { |record| insert_record(record) }
end
def create!(attributes = {})
create_record(attributes) { |record| insert_record(record, true) }
end
def columns
@reflection.columns(@reflection.options[:join_table], "#{@reflection.options[:join_table]} Columns")
end
def reset_column_information
@reflection.reset_column_information
end
def has_primary_key?
@has_primary_key ||= @owner.connection.supports_primary_key? && @owner.connection.primary_key(@reflection.options[:join_table])
end
protected
def construct_find_options!(options)
options[:joins] = Arel::SqlLiteral.new(@scope[:find][:joins])
options[:readonly] = finding_with_ambiguous_select?(options[:select] || @reflection.options[:select])
options[:select] ||= (@reflection.options[:select] || Arel::SqlLiteral.new('*'))
end
def count_records
load_target.size
end
def insert_record(record, force = true, validate = true)
if record.new_record?
return false unless save_record(record, force, validate)
end
if @reflection.options[:insert_sql]
@owner.connection.insert(interpolate_sql(@reflection.options[:insert_sql], record))
else
relation = Arel::Table.new(@reflection.options[:join_table])
timestamps = record_timestamp_columns(record)
timezone = record.send(:current_time_from_proper_timezone) if timestamps.any?
attributes = columns.map do |column|
name = column.name
value = case name.to_s
when @reflection.primary_key_name.to_s
@owner.id
when @reflection.association_foreign_key.to_s
record.id
when *timestamps
timezone
else
@owner.send(:quote_value, record[name], column) if record.has_attribute?(name)
end
[relation[name], value] unless value.nil?
end
stmt = relation.compile_insert Hash[attributes]
@owner.connection.insert stmt.to_sql
end
true
end
def delete_records(records)
if sql = @reflection.options[:delete_sql]
records.each { |record| @owner.connection.delete(interpolate_sql(sql, record)) }
else
relation = Arel::Table.new(@reflection.options[:join_table])
stmt = relation.where(relation[@reflection.primary_key_name].eq(@owner.id).
and(relation[@reflection.association_foreign_key].in(records.map { |x| x.id }.compact))
).compile_delete
@owner.connection.delete stmt.to_sql
end
end
def construct_joins
"INNER JOIN #{@owner.connection.quote_table_name @reflection.options[:join_table]} ON #{@reflection.quoted_table_name}.#{@reflection.klass.primary_key} = #{@owner.connection.quote_table_name @reflection.options[:join_table]}.#{@reflection.association_foreign_key}"
end
def construct_conditions
sql = "#{@owner.connection.quote_table_name @reflection.options[:join_table]}.#{@reflection.primary_key_name} = #{owner_quoted_id} "
sql << " AND (#{conditions})" if conditions
sql
end
def construct_find_scope
{
:conditions => construct_conditions,
:joins => construct_joins,
:readonly => false,
:order => @reflection.options[:order],
:include => @reflection.options[:include],
:limit => @reflection.options[:limit]
}
end
# Join tables with additional columns on top of the two foreign keys must be considered
# ambiguous unless a select clause has been explicitly defined. Otherwise you can get
# broken records back, if, for example, the join column also has an id column. This will
# then overwrite the id column of the records coming back.
def finding_with_ambiguous_select?(select_clause)
!select_clause && columns.size != 2
end
private
def create_record(attributes, &block)
# Can't use Base.create because the foreign key may be a protected attribute.
ensure_owner_is_persisted!
if attributes.is_a?(Array)
attributes.collect { |attr| create(attr) }
else
build_record(attributes, &block)
end
end
def record_timestamp_columns(record)
if record.record_timestamps
record.send(:all_timestamp_attributes).map { |x| x.to_s }
else
[]
end
end
end
end
end