【转载】ABAP-如何读取内表的字段名称
原文地址：ABAP-如何读取内表的字段名称
*&---------------------------------------------------------------------*
*& Report ZTRAINING29 如何得到内表的字段名称与字段类型 *
*& T-code *
*&---------------------------------------------------------------------*
*& Created by Xavery hsueh(薛现军) on 2011-06-08 *
*& Last edited date: *
*&---------------------------------------------------------------------*
REPORT ztraining29 NO STANDARD PAGE HEADING .
************************************************************************
** 声明数据库表 Declaration of database **
************************************************************************
TABLES:mara,
makt. "
************************************************************************
** 定义结构类型 Define the structure's type **
************************************************************************
* 物料编号的内表
TYPES:BEGIN OF typ_mara,
matnr TYPE matnr,
meins TYPE meins,
maktx TYPE maktx,
END OF typ_mara.
* 保存内表的字段名称
TYPES:BEGIN OF typ_field,
fieldnm TYPE txt30,
END OF typ_field.
************************************************************************
** 定义变量与内表 Define the variants and Internal tables **
************************************************************************
DATA:gt_mara TYPE TABLE OF typ_mara WITH HEADER LINE.
DATA:gt_field TYPE TABLE OF typ_field WITH HEADER LINE.
DATA:cl_descr TYPE REF TO cl_abap_structdescr.
FIELD-SYMBOLS:<fs_comp> TYPE abap_compdescr.
FIELD-SYMBOLS <fs_name> TYPE ANY.
************************************************************************
** 宏定义 Define the macro **
************************************************************************
DEFINE mcr_range.
clear &1.
&1-sign = 'I'.
&1-option = &2.
&1-low = &3.
&1-high = &4.
append &1.
END-OF-DEFINITION.
************************************************************************
** 选择屏幕 Customize the selection-screen **
************************************************************************
SELECTION-SCREEN BEGIN OF BLOCK xavery WITH FRAME TITLE text_001.
PARAMETERS: p_erdat TYPE erdat DEFAULT sy-datum. "统计日期
SELECT-OPTIONS s_matnr FOR mara-matnr. "物料编号
SELECTION-SCREEN END OF BLOCK xavery.
************************************************************************
** 执行程序事件 Executing the program's events **
************************************************************************
INITIALIZATION.
PERFORM sub_init_cond.
START-OF-SELECTION.
PERFORM sub_process_fieldname.
END-OF-SELECTION.
*@---------------------------------------------------------------------*
*@ Form SUB_INIT_COND
*@---------------------------------------------------------------------*
* 初始化选择条件
*----------------------------------------------------------------------*
FORM sub_init_cond .
text_001 = '选择屏幕'.
ENDFORM. " SUB_INIT_COND
*&---------------------------------------------------------------------*
*& Form sub_process_fieldname
*&---------------------------------------------------------------------*
* 取得内表字段名称与类型
*----------------------------------------------------------------------*
FORM sub_process_fieldname .
DATA:g_fieldnm TYPE txt30.
cl_descr ?= cl_abap_typedescr=>describe_by_data( gt_mara ).
LOOP AT cl_descr->components ASSIGNING <fs_comp>.
WRITE: / <fs_comp>-name, "字段名称
<fs_comp>-type_kind, "字段类型
<fs_comp>-length, "字段长度
<fs_comp>-decimals. "字段小数位
APPEND <fs_comp>-name TO gt_field.
ENDLOOP.
LOOP AT gt_field.
CONCATENATE 'GT_MARA-' gt_field-fieldnm INTO gt_field.
MODIFY gt_field.
ENDLOOP.
SELECT * FROM mara
INTO CORRESPONDING FIELDS OF TABLE gt_mara
WHERE matnr IN s_matnr.
* 使用得到的字段名称，输出字段结果
LOOP AT gt_mara.
WRITE /.
LOOP AT gt_field.
ASSIGN (gt_field-fieldnm) TO <fs_name>.
WRITE: <fs_name>.
ENDLOOP.
ENDLOOP.
ENDFORM. " sub_process_fieldname
*& Report ZTRAINING29 如何得到内表的字段名称与字段类型 *
*& T-code *
*&---------------------------------------------------------------------*
*& Created by Xavery hsueh(薛现军) on 2011-06-08 *
*& Last edited date: *
*&---------------------------------------------------------------------*
REPORT ztraining29 NO STANDARD PAGE HEADING .
************************************************************************
** 声明数据库表 Declaration of database **
************************************************************************
TABLES:mara,
makt. "
************************************************************************
** 定义结构类型 Define the structure's type **
************************************************************************
* 物料编号的内表
TYPES:BEGIN OF typ_mara,
matnr TYPE matnr,
meins TYPE meins,
maktx TYPE maktx,
END OF typ_mara.
* 保存内表的字段名称
TYPES:BEGIN OF typ_field,
fieldnm TYPE txt30,
END OF typ_field.
************************************************************************
** 定义变量与内表 Define the variants and Internal tables **
************************************************************************
DATA:gt_mara TYPE TABLE OF typ_mara WITH HEADER LINE.
DATA:gt_field TYPE TABLE OF typ_field WITH HEADER LINE.
DATA:cl_descr TYPE REF TO cl_abap_structdescr.
FIELD-SYMBOLS:<fs_comp> TYPE abap_compdescr.
FIELD-SYMBOLS <fs_name> TYPE ANY.
************************************************************************
** 宏定义 Define the macro **
************************************************************************
DEFINE mcr_range.
clear &1.
&1-sign = 'I'.
&1-option = &2.
&1-low = &3.
&1-high = &4.
append &1.
END-OF-DEFINITION.
************************************************************************
** 选择屏幕 Customize the selection-screen **
************************************************************************
SELECTION-SCREEN BEGIN OF BLOCK xavery WITH FRAME TITLE text_001.
PARAMETERS: p_erdat TYPE erdat DEFAULT sy-datum. "统计日期
SELECT-OPTIONS s_matnr FOR mara-matnr. "物料编号
SELECTION-SCREEN END OF BLOCK xavery.
************************************************************************
** 执行程序事件 Executing the program's events **
************************************************************************
INITIALIZATION.
PERFORM sub_init_cond.
START-OF-SELECTION.
PERFORM sub_process_fieldname.
END-OF-SELECTION.
*@---------------------------------------------------------------------*
*@ Form SUB_INIT_COND
*@---------------------------------------------------------------------*
* 初始化选择条件
*----------------------------------------------------------------------*
FORM sub_init_cond .
text_001 = '选择屏幕'.
ENDFORM. " SUB_INIT_COND
*&---------------------------------------------------------------------*
*& Form sub_process_fieldname
*&---------------------------------------------------------------------*
* 取得内表字段名称与类型
*----------------------------------------------------------------------*
FORM sub_process_fieldname .
DATA:g_fieldnm TYPE txt30.
cl_descr ?= cl_abap_typedescr=>describe_by_data( gt_mara ).
LOOP AT cl_descr->components ASSIGNING <fs_comp>.
WRITE: / <fs_comp>-name, "字段名称
<fs_comp>-type_kind, "字段类型
<fs_comp>-length, "字段长度
<fs_comp>-decimals. "字段小数位
APPEND <fs_comp>-name TO gt_field.
ENDLOOP.
LOOP AT gt_field.
CONCATENATE 'GT_MARA-' gt_field-fieldnm INTO gt_field.
MODIFY gt_field.
ENDLOOP.
SELECT * FROM mara
INTO CORRESPONDING FIELDS OF TABLE gt_mara
WHERE matnr IN s_matnr.
* 使用得到的字段名称，输出字段结果
LOOP AT gt_mara.
WRITE /.
LOOP AT gt_field.
ASSIGN (gt_field-fieldnm) TO <fs_name>.
WRITE: <fs_name>.
ENDLOOP.
ENDLOOP.
ENDFORM. " sub_process_fieldname
