    # File lib/active_record/vendor/db2.rb, line 128
        def prepare(sql)
          @sql = sql
          check_rc(SQLPrepare(@handle, sql))
          rc, @numParms = SQLNumParams(@handle) #number of question marks
          check_rc(rc)
          #--------------------------------------------------------------------------
          # parameter attributes are stored in instance variable @parmArray so that
          # they are available when execute method is called.
          #--------------------------------------------------------------------------
          if @numParms > 0           # get parameter marker attributes
            1.upto(@numParms) do |i| # parameter number starts from 1
              rc, type, size, decimalDigits = SQLDescribeParam(@handle, i)
              check_rc(rc)
              @parmArray << Parameter.new(type, size, decimalDigits)
            end
          end
          @prepared = true
          self
        end