Dynamic ALV with field catalog and inner join

[Former Member]

Greetings fellow abap programmers.

Lets start of with that i am a new programmer learning my way trough error jungle.

I have a assignment to link three tables and display it in a ALV grid.

My question is as followed: How can i create a dynamic field catalog by using the internal table that has been defined and then pass this structure / catalog to reuse_alv_grid_merge.

What i like the program to do:

1. create a field catalog / structure based on the defined internal table structure.

2. pass this structure and the internal table data to 'REUSE_ALV_GRID_MERGE' or display.

And yes i have done research before posting.

like there are three ways to use ALV: Manuel, automatic, semi, automatic.

1. First off all i refuse to code the Manuel way,

2. the automatic works but it forces me to create a database table that is matching internal table.

3. semi automatic does not quite what i what to do.

My code and comments are in bold for extra information:

REPORT z_training_4_material_report.

< Table structure is defined, but removed to compact code>

data : 
           pt_fieldcat         type                   lvc_t_fcat,
           wa_mara           type                   ts_mara,
           it_mara2            type standard table of ts_mara,
           it_mara              type standard table of ts_mara with header line initial size 0.



selection-screen begin of block range_select.
select-options : so_matnr for lv_mat_nr.
select-options : so_plnnr for lv_plant.
selection-screen end of block range_select.


select mara~matnr makt~maktx mara~brgew mara~ntgew marc~werks t024d~dsnam mara~meins marc~strgr marc~disls
into corresponding fields of table it_mara from mara

inner join marc on marc~matnr = mara~matnr
inner join makt on makt~matnr = mara~matnr
inner join t024d on marc~werks = t024d~werks

where mara~matnr between so_matnr-low and so_matnr-high.

<found this form code on forum and tried to use it to create the field catalog but it has a type issue. when looking this up i tried changing the type but that did not do it. >

perform create_fieldcatalog

using it_mara2

changing pt_fieldcat.

call function 'REUSE_ALV_GRID_MERGE'
   exporting
     it_fieldcat = pt_fieldcat
   tables
     t_outtab    = it_mara.
.

*&---------------------------------------------------------------------*
*& Form  create_fieldcatalog
*&---------------------------------------------------------------------*
* Create a field catalogue from any internal table
*----------------------------------------------------------------------*
*      -->PT_TABLE     Internal table
*      -->PT_FIELDCAT  Field Catalogue
*----------------------------------------------------------------------*
form  create_fieldcatalog
        using     pt_table     type standard table
        changing  pt_fieldcat  type lvc_t_fcat.

   data:
     lr_tabdescr type ref to cl_abap_structdescr
   , lr_data     type ref to data
   , lt_dfies    type ddfields
   , ls_dfies    type dfies
   , ls_fieldcat type lvc_s_fcat
   .

   clear pt_fieldcat.

   create data lr_data like line of pt_table.

   lr_tabdescr ?= cl_abap_structdescr=>describe_by_data_ref( lr_data ).

   lt_dfies = cl_salv_data_descr=>read_structdescr( lr_tabdescr ).

   loop at lt_dfies
   into    ls_dfies.

     clear ls_fieldcat.

     move-corresponding ls_dfies to ls_fieldcat.

     append ls_fieldcat to pt_fieldcat.

   endloop.

endform.                    "create_fieldcatalog

[Former Member]

Hello,

After some further research i finally found a solution to create a field catalog automatically.

there were different approaches like using a class. if other poeple stumble uppon this problem i hereby link the references used by myself to come to the solution.

Sources:

Working example and simple use

Create conversion based on abap class

Variant ALV programs

ALV guide