ABAP 7.40 - limits of MESH?

Question

Are there any know limits of meshes? I know, that the table-types need to be non-generic.

But can it be, that a 5-key-dbtable as base for local table-type-definition is not ok ??? (I really doubt it).

I simply have a two-level table hierarchy and want to retrieve ALL mesh-results of the second table py passing the key of the main-table. I only have forward-associations, have a look, this is, what I try to achieve (pattern found on some website):

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.

This dumps with "CX_ITAB_LINE_NOT_FOUND".

But I did it exactly, how it was written. And, I think, this must work, because I use this approach to get a subset from another table based on the keyentries of the first table. I tried to add additional association-params, which did not dump anymore, but anyway, just returned only one record of the second table.

I seem to overlook some basic thingy, but which one ?

I guess it should be DATA(chk) = ls_mesh-types\to_excludes[ ls_mesh-types[ order_type = wf_check ] ]., no? — Sandra Rossi
Yes, that is the one revealing just one result. I want all at once. — icbytes
Okay, I was wrong, a mesh used as an expression returns only one line as stated in the documentation, that's different from the case you are using it with LOOP AT for instance. I'll post an answer with more details. — Sandra Rossi

Sandra Rossi Sandra Rossi · Accepted Answer · 2018-06-08T06:58:59

As stated in the 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".

PS: there are the programs DEMO_MESH_EXPRESSION* to play with mesh path expressions. Here is a shorter standalone demo program, taken from the 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 - limits of MESH?

1 Answers