UP TO X ROWS 用法

UP TO X ROWS 一般用在取限制记录数。这种用法在取多条数据的针对某一字段特别有用。如下：

取最近成本估算。

  DATA:it_keko LIKE keko OCCURS 0 WITH HEADER LINE.
  CLEAR:xkeko,zco_sub_com,zco_sub_com[].

  SELECT * INTO TABLE it_keko FROM keko UP TO 1 ROWS
      WHERE werks = werks AND
         matnr = matnr AND
          klvar = 'ZPC1' AND
          loekz <> 'X' AND
          kadat <= kadky AND
          bidat >= kadky
          AND tvers = '01'
          AND bwvar = '001' AND keko~mandt = sy-mandt
          ORDER BY kadky DESCENDING .