vendor/rails/activerecord/lib/active_record/associations/has_and_belongs_to_many_association.rb

   1 module ActiveRecord
   2   module Associations
   3     class HasAndBelongsToManyAssociation < AssociationCollection #:nodoc:
   4       def create(attributes = {})
   5         create_record(attributes) { |record| insert_record(record) }
   6       end
   7
   8       def create!(attributes = {})
   9         create_record(attributes) { |record| insert_record(record, true) }
  10       end
  11
  12       protected
  13         def construct_find_options!(options)
  14           options[:joins]      = @join_sql
  15           options[:readonly]   = finding_with_ambiguous_select?(options[:select] || @reflection.options[:select])
  16           options[:select]   ||= (@reflection.options[:select] || '*')
  17         end
  18
  19         def count_records
  20           load_target.size
  21         end
  22
  23         def insert_record(record, force=true)
  24           if record.new_record?
  25             if force
  26               record.save!
  27             else
  28               return false unless record.save
  29             end
  30           end
  31
  32           if @reflection.options[:insert_sql]
  33             @owner.connection.insert(interpolate_sql(@reflection.options[:insert_sql], record))
  34           else
  35             columns = @owner.connection.columns(@reflection.options[:join_table], "#{@reflection.options[:join_table]} Columns")
  36
  37             attributes = columns.inject({}) do |attrs, column|
  38               case column.name.to_s
  39                 when @reflection.primary_key_name.to_s
  40                   attrs[column.name] = owner_quoted_id
  41                 when @reflection.association_foreign_key.to_s
  42                   attrs[column.name] = record.quoted_id
  43                 else
  44                   if record.has_attribute?(column.name)
  45                     value = @owner.send(:quote_value, record[column.name], column)
  46                     attrs[column.name] = value unless value.nil?
  47                   end
  48               end
  49               attrs
  50             end
  51
  52             sql =
  53               "INSERT INTO #{@owner.connection.quote_table_name @reflection.options[:join_table]} (#{@owner.send(:quoted_column_names, attributes).join(', ')}) " +
  54               "VALUES (#{attributes.values.join(', ')})"
  55
  56             @owner.connection.insert(sql)
  57           end
  58
  59           return true
  60         end
  61
  62         def delete_records(records)
  63           if sql = @reflection.options[:delete_sql]
  64             records.each { |record| @owner.connection.delete(interpolate_sql(sql, record)) }
  65           else
  66             ids = quoted_record_ids(records)
  67             sql = "DELETE FROM #{@owner.connection.quote_table_name @reflection.options[:join_table]} WHERE #{@reflection.primary_key_name} = #{owner_quoted_id} AND #{@reflection.association_foreign_key} IN (#{ids})"
  68             @owner.connection.delete(sql)
  69           end
  70         end
  71
  72         def construct_sql
  73           if @reflection.options[:finder_sql]
  74             @finder_sql = interpolate_sql(@reflection.options[:finder_sql])
  75           else
  76             @finder_sql = "#{@owner.connection.quote_table_name @reflection.options[:join_table]}.#{@reflection.primary_key_name} = #{owner_quoted_id} "
  77             @finder_sql << " AND (#{conditions})" if conditions
  78           end
  79
  80           @join_sql = "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}"
  81
  82           if @reflection.options[:counter_sql]
  83             @counter_sql = interpolate_sql(@reflection.options[:counter_sql])
  84           elsif @reflection.options[:finder_sql]
  85             # replace the SELECT clause with COUNT(*), preserving any hints within /* ... */
  86             @reflection.options[:counter_sql] = @reflection.options[:finder_sql].sub(/SELECT (\/\*.*?\*\/ )?(.*)\bFROM\b/im) { "SELECT #{$1}COUNT(*) FROM" }
  87             @counter_sql = interpolate_sql(@reflection.options[:counter_sql])
  88           else
  89             @counter_sql = @finder_sql
  90           end
  91         end
  92
  93         def construct_scope
  94           { :find => {  :conditions => @finder_sql,
  95                         :joins => @join_sql,
  96                         :readonly => false,
  97                         :order => @reflection.options[:order],
  98                         :include => @reflection.options[:include],
  99                         :limit => @reflection.options[:limit] } }
 100         end
 101
 102         # Join tables with additional columns on top of the two foreign keys must be considered ambiguous unless a select
 103         # clause has been explicitly defined. Otherwise you can get broken records back, if, for example, the join column also has
 104         # an id column. This will then overwrite the id column of the records coming back.
 105         def finding_with_ambiguous_select?(select_clause)
 106           !select_clause && @owner.connection.columns(@reflection.options[:join_table], "Join Table Columns").size != 2
 107         end
 108
 109       private
 110         def create_record(attributes, &block)
 111           # Can't use Base.create because the foreign key may be a protected attribute.
 112           ensure_owner_is_not_new
 113           if attributes.is_a?(Array)
 114             attributes.collect { |attr| create(attr) }
 115           else
 116             build_record(attributes, &block)
 117           end
 118         end
 119     end
 120   end
 121 end