如何动态调用字段符号

Question

假设我有一个分配给字段符号的标准结构。 有没有办法将变量传递给动态调用的字段符号？

例如：

  DATA: lt_mara            TYPE STANDARD TABLE OF mara WITH HEADER LINE,
        parameter_name(10) TYPE c.

  parameter_name = 'MATNR'.

  LOOP AT lt_mara ASSIGNING FIELD-SYMBOL(<fs_lt_mara>).
    WRITE: <fs_lt_mara>-(parameter_name).
  ENDLOOP.

其中parameter_name包含在mara结构中可用的列名。

Answer 1

可以使用 ASSIGN 指令。 下面是一个例子：

DATA:   lt_mara            TYPE STANDARD TABLE OF mara WITH HEADER LINE,
        parameter_name(10) TYPE c.

parameter_name = 'MATNR'.

FIELD-SYMBOLS: <fs_lt_mara> TYPE mara,
               <fs_value>   TYPE any.

SELECT * FROM mara UP TO 10 ROWS INTO TABLE lt_mara.

LOOP AT lt_mara ASSIGNING <fs_lt_mara>.

  ASSIGN COMPONENT parameter_name OF STRUCTURE <fs_lt_mara> TO <fs_value>.
  IF sy-subrc = 0.
    WRITE: / <fs_value>.
  ENDIF.

ENDLOOP.

Answer 2

我提供了另一个ASSIGN示例。 你做一次ASSIGN并做一个LOOP INTO 。

DATA: lt_mara  TYPE STANDARD TABLE OF mara,
      ls_mara  TYPE mara,
      lc_matnr TYPE char5 VALUE 'MATNR'.


FIELD-SYMBOLS: <ls_mara>  TYPE mara,
               <lv_value> TYPE any.

SELECT * FROM mara UP TO 10 ROWS INTO TABLE lt_mara.

ASSIGN COMPONENT lc_matnr OF STRUCTURE ls_mara TO <lv_value>.

CHECK <lv_value> IS ASSIGNED.

LOOP AT lt_mara INTO ls_mara.

    WRITE: / <lv_value>.

ENDLOOP.