abap - 为什么类型不兼容？

Question

我有一个 3 维表(带有嵌套表的表)，我的目标是删除内表中 FIELDNAME 等于 'SCAN_ID'< 的行:

TYPES : BEGIN OF ty_cell,
          fieldname TYPE lvc_fname,
        END OF ty_cell,
        ty_celltab TYPE STANDARD TABLE OF ty_cell WITH EMPTY KEY.
TYPES : BEGIN OF ty_line,
          celltab TYPE ty_celltab,
        END OF ty_line,
        zatool_t_doc_input TYPE STANDARD TABLE OF ty_line WITH EMPTY KEY.

DATA(it_doc_input) = VALUE zatool_t_doc_input( ( celltab = VALUE #( ( fieldname = 'SCAN_ID' ) ) ) ).

DATA(rt_doc_input) = REDUCE zatool_t_doc_input( " <=== line of syntax error
      INIT lt_doc_input = VALUE zatool_t_doc_input( )
      FOR ls_doc_input IN it_doc_input
      NEXT lt_doc_input = VALUE #( 
            BASE ls_doc_input 
            celltab = FILTER #( 
                  ls_doc_input-celltab 
                  WHERE fieldname <> CONV lvc_fname( 'SCAN_ID' ) ) ) ).

编译器给出了这个语法错误:

The type of "LS_DOC_INPUT" cannot be converted to the type of "LT_DOC_INPUT"

哪里出错了？

Answer 1

使用如下所示的“表格理解”，您可以获得带有过滤单元格标签的表格:

TYPES:
  BEGIN OF zatool_t_doc_input_s,
    field1  TYPE c,
    field2  TYPE c,
    celltab TYPE lvc_t_styl,
  END OF zatool_t_doc_input_s,
  zatool_t_doc_input TYPE STANDARD TABLE OF zatool_t_doc_input_s WITH EMPTY KEY.

DATA(it_doc_input) = VALUE zatool_t_doc_input(
                      ( field1 = 'A' field2 = 'B' celltab = VALUE #( ( fieldname = 'SCAN_ID' ) ) )
                      ( field1 = 'C' field2 = 'D' celltab = VALUE #( ( fieldname = 'USER_ID' ) ) )
                      ( field1 = 'C' field2 = 'D' celltab = VALUE #( ( fieldname = 'SCAN_ID' ) ) )
                      ( field1 = 'E' field2 = 'F' celltab = VALUE #( ( fieldname = 'SYST_ID' ) ) )
                     ).

DATA(rt_doc_input) =  VALUE zatool_t_doc_input(
                      FOR ls_doc_input IN it_doc_input (
                        VALUE #( BASE ls_doc_input
                                 celltab = FILTER #( ls_doc_input-celltab
                                           WHERE fieldname <> CONV lvc_fname( 'SCAN_ID' ) ) ) ) ).

关于语法错误，正如@Florian 指出的那样，问题是当使用BASE 结构(在本例中为ls_doc_input)时，相应的VALUE #(返回一个结构体，如果VALUE要返回一个表，BASE也必须使用一个表。

无论如何，即使你用这样的东西绕过 BASE 语法错误

DATA(rt_doc_input) =
  REDUCE #( INIT lt_doc_input = VALUE zatool_t_doc_input( )
            FOR ls_doc_input IN it_doc_input
            NEXT lt_doc_input = VALUE #( ( field1  = ls_doc_input-field1
                                           field2  = ls_doc_input-field2
                                           celltab = FILTER #( ls_doc_input-celltab
                                                     WHERE fieldname <> CONV lvc_fname( 'SCAN_ID' ) ) 
                                       ) ) 
           ). "reduces the original table to a single line (albeit with celltab filtered)

或者甚至是等效的，使用 BASE 来避免单独的字段分配

DATA(rt_doc_input) =
  REDUCE #( INIT lt_doc_input = VALUE zatool_t_doc_input( )
            FOR ls_doc_input IN it_doc_input
            NEXT lt_doc_input =
              VALUE #(
                ( VALUE #( BASE ls_doc_input
                           celltab = FILTER #( ls_doc_input-celltab
                                     WHERE fieldname <> CONV lvc_fname( 'SCAN_ID' ) )
                          ) "VALUE: table line using BASE
                ) " VALUE: table row
              ) "VALUE: table
           ). "reduces the original table to a single line (albeit with celltab filtered)

它仍然无法实现我猜您的目标，因为它会将 it_doc_input 缩减为一行。