abap - 将 SELECT 结果分配给字段符号 GETWA_NOT_ASSIGNED

Question

我很困惑为什么注释掉的查询不起作用。

REPORT  z_hello_world_local.

TYPES:  BEGIN OF bkpf_type,
          xblnr          TYPE bkpf-xblnr,
        END OF bkpf_type.

DATA: t_bkpf                 TYPE TABLE OF bkpf_type.

FIELD-SYMBOLS:  <bkpf>        TYPE bkpf_type.


*This query does not work?
*SELECT xblnr
*      INTO CORRESPONDING FIELDS OF <bkpf> UP TO 1 ROWS
*      FROM bkpf
*      WHERE belnr = '1800001017'.
*    ENDSELECT.
*
DATA: t_xblnr TYPE bkpf-xblnr.

*This query works and in my head it is roughly the same thing.
SELECT SINGLE xblnr
      INTO t_xblnr
      FROM bkpf
      WHERE belnr = '1800001017'.


write 'Done'.

如果我运行注释掉的查询，我会收到错误:

Runtime Errors GETWA_NOT_ASSIGNED Date and Time
08/26/2009 19:54:19

Short text Field symbol has not yet been assigned.

为什么我会收到此运行时错误？

Answer 1

我假设(基于错误和我实际上看不到的代码片段)您正在尝试将数据直接选择到字段符号中。你不能那样做。字段符号不是内存区域，它(基本上)是一个指针。

您可以执行以下操作之一:

data: wa_bkpf type bkpf_type.

select xblnr
  into corresponding fields of wa_bkpf
  up to 1 rows
  from bkpf
  where xblnr = '1800001017'.
endselect.

或

field-symbols: <bkpf> type bkpf_type.
append initial line to t_bkpf assigning <bkpf>.
select xlbnr
  into corresponding fields <bkpf>
  up to 1 rows
  from bkpf
  where xblnr = '1800001017'.
endselect.

在本例中，您将字段符号指向已添加到内部表中的新行。

或

select xblnr
  into corresponding fields of table t_bkpf
  from bkpf
  where xlbnr = '1800001017'.

在这种情况下，您将检索所有匹配的文档并将它们直接放入您的内部表中。