ABAP 7.40 - MESH 的限制？

Question

网格是否有已知的限制？我知道，table 类型需要是非泛型的。

但是，5-key-dbtable 作为本地 table-type-definition 的基础是不是可以？？？（我真的很怀疑）

我只有一个两级 table 层次结构，并且想要检索第二个 table py 的所有网格结果并传递主 table 的密钥。我只有forward-associations，看看，这就是我试图实现的（在一些网站上找到的模式）：

TYPES: lty_types    TYPE STANDARD TABLE OF zordertype WITH NON-UNIQUE KEY table_line,
       lty_excludes TYPE STANDARD TABLE OF zexcludeorder WITH NON-UNIQUE key table_line.

DATA: lt_types    TYPE lty_types,
      lt_excludes TYPE lty_excludes.

TYPES:
  BEGIN OF MESH ty_type_excludes,
    types    TYPE lty_types
               ASSOCIATION to_excludes
               TO excludes ON order_type = order_type,
    excludes TYPE lty_excludes,
  END OF MESH ty_type_excludes.

DATA: ls_mesh TYPE ty_type_excludes.

START-OF-SELECTION.

  SELECT * FROM zordertype
               INTO TABLE @lt_types
               ORDER BY order_type.

  SELECT * FROM zexcludeorder
           INTO TABLE @lt_excludes
             ORDER BY order_type.

  ls_mesh-types    = lt_types.
  ls_mesh-excludes = lt_excludes.

  DATA wf_check TYPE zorder_type VALUE 'CAT'.

  DATA(chk) = ls_mesh-types\to_excludes[ wf_check ].

  break myuser.

此转储 "CX_ITAB_LINE_NOT_FOUND"。

但我确实做到了，它是如何写的。而且，我认为，这一定有效，因为我使用这种方法根据第一个 table 的键条目从另一个 table 获取子集。我试图添加额外的关联参数，它不再转储，但无论如何，只返回了第二个 table.

的一条记录

我似乎忽略了一些基本的东西，但是哪一个呢？

Answer 1

如 ABAP documentation, a mesh path expression、"the result of a mesh path expression is a row from the last path node of the mesh path" 中所述。

PS：有程序DEMO_MESH_EXPRESSION* 可以玩网格路径表达式。这是一个较短的独立演示程序，摘自 chapter 12 of blog post ABAP 7.40 Quick Reference :

TYPES: BEGIN OF t_manager,
 name   TYPE char10,
 salary TYPE int4,
END OF t_manager,
 tt_manager TYPE SORTED TABLE OF t_manager WITH UNIQUE KEY name.

TYPES: BEGIN OF t_developer,
 name    TYPE char10,
 salary  TYPE int4,
 manager TYPE char10,
END OF t_developer,

 tt_developer TYPE SORTED TABLE OF t_developer WITH UNIQUE KEY name.

TYPES: BEGIN OF MESH m_team,
         managers   TYPE tt_manager  ASSOCIATION my_employees TO developers
                                                            ON manager = name,
         developers TYPE tt_developer ASSOCIATION my_manager TO managers
                                                            ON name = manager,
       END OF MESH m_team.

DATA: ls_team TYPE m_team.

LS_TEAM-MANAGERS = value #(
( Name = 'Jason'  Salary = 3000 )
( Name = 'Thomas' Salary = 3200 ) ).

LS_TEAM-DEVELOPERS = value #(
( Name = 'Bob'   Salary = 2100 manager = 'Jason' )
( Name = 'David' Salary = 2000 manager = 'Thomas' )
( Name = 'Jack'  Salary = 1000 manager = 'Thomas' )
( Name = 'Jerry' Salary = 1000 manager = 'Jason' )
( Name = 'John'  Salary = 2100 manager = 'Thomas' )
( Name = 'Tom'   Salary = 2000 manager = 'Jason' ) ).

" Get details of Jerry's manager
ASSIGN ls_team-developers[ name = 'Jerry' ] TO FIELD-SYMBOL(<ls_jerry>).
DATA(ls_jmanager) = ls_team-developers\my_manager[ <ls_jerry> ].

WRITE: / |Jerry's manager: { ls_jmanager-name }|,30
                  |Salary: { ls_jmanager-salary }|.

" Get Thomas' developers
SKIP.
WRITE: / |Thomas' developers:|.

ASSIGN ls_team-managers[ name = 'Thomas' ] TO FIELD-SYMBOL(<ls_thomas>).
LOOP AT ls_team-managers\my_employees[ <ls_thomas> ]
        ASSIGNING FIELD-SYMBOL(<ls_emp>).

  WRITE: / |Employee name: { <ls_emp>-name }|.
ENDLOOP.

" the result of a mesh path expression is a row from the last path node of the mesh path
DATA(thomas_employee) = ls_team-managers\my_employees[ <ls_thomas> ].
SKIP.
WRITE: / |Thomas's "any" Employee name: { thomas_employee-name }|.

ABAP 7.40 - MESH 的限制？

ABAP 7.40 - limits of MESH?

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