sql_for_insert

# File activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb, line 76
        def sql_for_insert(sql, pk, binds) # :nodoc:
          if pk.nil?
            # Extract the table from the insert sql. Yuck.
            table_ref = extract_table_ref_from_insert_sql(sql)
            pk = primary_key(table_ref) if table_ref
          end

          if pk = suppress_composite_primary_key(pk)
            sql = "#{sql} RETURNING #{quote_column_name(pk)}"
          end

          super
        end