Runtime structure creation

[Former Member]

Hello ABAP experts,

I would like to create a structure. This structure should have the field names that I select from a table value.

For example,

Let's say my select statement returns the value 'VALUE1', my structure definition should be

begin of stru1 ,

    'VALUE1'(20) type c,

    belnr type belnr,

    matnr type matnr,

end of stru1.

Is this possible? If so, can you please provide me a sample code?

Thank you,

Ram Kannan

Moderator message - FAQ. Unmarked as question & removed points allocated.

Message was edited by: Suhas Saha

[former_member226419]

Hi ,

Can you please elaborate little more?

select statement suppose returns multiple valuees in internal table like 'Val1','Val2' and 'val3'.

Then u need structure like,

begin of stru1 ,

    'VAL1'(20) type c,

    val2(20) type c,

    val3(20) type c,

end of stru1.

Am i getting right?

BR

Sumeet

[Former Member]

Hello,

For you requirement, you will need to create a dynamic internal table based in your fields received in your SELECT statement and use a field symbol structure to assign for future use.

You can use this content as reference: Dynamic Internal table - ABAP Development - SCN Wiki.

Focus in the FORM routine CREATE_DYNAMIC_ITAB, last 2 lines.

[former_member192854]

TYPES: BEGIN OF ty_struc,

         value1(20) TYPE c,

         belnr      TYPE belnr,

         matnr      TYPE matnr,

       END OF stru1.

Here you have the structure definition - or table definition.

DATA ls_struc TYPE ty_struc.

Gives you the structure at run time. If you mean creation via RTT, you should do:

DATA lr_data TYPE REF TO data.

CREATE DATA lr_data TYPE ty_struc.

And for the usage of the structure you should derefence it:

FIELD-SYMBOLS <fs_struc> TYPE any.

ASSIGN lr_data->* TO <fs_struc>.

Best,

Sander

[Former Member]

DATA: lt_fieldcat TYPE lvc_t_fcat.

1) Fill your fields into LT_FIELDCAT.

2) Then create a dynamic internal table using that field catalogue.

DATA: lt_dyn_table TYPE REF TO data,

      ls_structure TYPE REF TO data.

FIELD-SYMBOLS : <fs_dyn_table> TYPE ANY TABLE,

                             <fs_structure> TYPE any.

  CALL METHOD cl_alv_table_create=>create_dynamic_table

    EXPORTING

      it_fieldcatalog           = lt_fieldcat

    IMPORTING

      ep_table                  = lt_dyn_table

    EXCEPTIONS

      generate_subpool_dir_full = 1

      OTHERS                    = 2.

  ASSIGN lt_table->* TO <fs_table>.

3) Then create the structure dynamically.

  CREATE DATA ls_structure LIKE LINE OF <fs_table>.

  ASSIGN ls_structure->* TO <fs_structure>.

[Former Member]

It's fully correct. Basically, this is what you need to do.

[former_member192854]

Hi Renan,

can you explain to me what an ALV fieldcategory has to do with dynamically creating a table?

Best,

Sander

[Former Member]

Hey Sander,

Basically the requirement of our friend is: create a structure with dynamic columns (will come from a database table).

So in this case, we can't define previous a type to cast a structure or a internal table using the command CREATE DATA. For solve this, we have the option to use the static method CREATE_DYNAMIC_TABLE from class CL_ALV_TABLE_CREATE based on a fieldcatalog.

The fields defined in the fieldcatalog table will be our "type" to create the dynamic internal table, like is to create ALV columns in a ALV Report.

The code of illustrate it in a good way.

[Former Member]

If you want more technical details, check the include "LSKBHF06" where the actual dynamic table creation takes place.

[former_member192854]

Hey Renan,

ok, of course that's also an applicable solution. I guess I missed the dynamic field part in the question.

Best,

Sander

[SuhaSaha]

Hello All,

can you explain to me what an ALV fieldcategory has to do with dynamically creating a table?

This method of creating dynamic runtime structures is no longer necessary if you have the RTTS classes available. ( Too many threads on this topic)

cl_alv_table_create=>create_dynamic_table( ) method calls GENERATE SUBROUTINE POOL internally which has it's own disadvantages. (Also discussed in the forums & highlighted in the SAP documentation)

I don't understand why people do not search before posting their question.

BR,

Suhas

[former_member192854]

My point exactly. So Ram, you could also consider the solution provided below.

REPORT  z_example_rtt_comp_create.

 DATA gt_component TYPE cl_abap_structdescr=>component_table.

 *----------------------------------------------------------------------*
 *       CLASS lcl_comp DEFINITION
 *----------------------------------------------------------------------*
 *
 *----------------------------------------------------------------------*
 CLASS lcl_comp DEFINITION.
   PUBLIC SECTION.
     CLASS-METHODS add_field
       IMPORTING
         iv_field    TYPE fieldname
         iv_rollname TYPE any.
     CLASS-METHODS get_component
       RETURNING
         value(rt_component) TYPE cl_abap_structdescr=>component_table.

   PRIVATE SECTION.
     CLASS-DATA mt_component TYPE cl_abap_structdescr=>component_table.

 ENDCLASS.                    "lcl_comp DEFINITION
 *----------------------------------------------------------------------*
 *       CLASS lcl_comp IMPLEMENTATION
 *----------------------------------------------------------------------*
 *
 *----------------------------------------------------------------------*
 CLASS lcl_comp IMPLEMENTATION.
   METHOD add_field.
     DATA ls_component                    TYPE cl_abap_structdescr=>component.

     ls_component-name = iv_field.
     ls_component-type ?= cl_abap_datadescr=>describe_by_name( iv_rollname ).
     INSERT ls_component INTO TABLE mt_component.
   ENDMETHOD.                    "add_field

   METHOD get_component.
     rt_component[] = mt_component[].
   ENDMETHOD.                    "get_component
 ENDCLASS.                    "lcl_comp IMPLEMENTATION

 START-OF-SELECTION.

   lcl_comp=>add_field(
     iv_field    = 'VALUE1'
     iv_rollname = 'CHAR20' ).                               "#EC NOTEXT
   lcl_comp=>add_field(
     iv_field    = 'BELNR'
     iv_rollname = 'BELNR' ).                                "#EC NOTEXT
   lcl_comp=>add_field(
     iv_field    = 'MATNR'
     iv_rollname = 'MATNR' ).                                "#EC NOTEXT
 * INSERT ANY ADDITIONAL VALUES YOU LIKE

   gt_component = lcl_comp=>get_component( ).
   DATA lo_struct_type TYPE REF TO cl_abap_structdescr.
   DATA lo_table_type TYPE REF TO cl_abap_tabledescr.
   DATA lx_root TYPE REF TO cx_root.

   TRY.
 * RTT structure type handler
       lo_struct_type  ?= cl_abap_structdescr=>create( 
                            p_components = gt_component ).
 * RTT Table type handler - based on structured type)
       lo_table_type = cl_abap_tabledescr=>create( 
                         p_line_type = lo_struct_type ).
     CATCH cx_sy_struct_attributes INTO lx_root.
       sy-msgv1 = lx_root->if_message~get_text( ).
       MESSAGE e398(00) WITH sy-msgv1.
       EXIT.
   ENDTRY.

   DATA lr_table TYPE REF TO data.
   DATA lr_struct TYPE REF TO data.

   FIELD-SYMBOLS <ft> TYPE ANY TABLE.
   FIELD-SYMBOLS <fs> TYPE ANY.

 * Creation and dereferencing of the table
   CREATE DATA lr_table TYPE HANDLE lo_table_type.
   ASSIGN lr_table->* TO <ft>.
 * Creation and dereferencing of the structure
   CREATE DATA lr_struct TYPE HANDLE lo_struct_type.
   ASSIGN lr_struct->* TO <fs>.

[Former Member]

Thank you everyone who answered the question...