Question Re: Getting database table keys via RTTS in Technology Q&A

Getting database table keys via RTTS

Astashonok — Sun, 30 Jul 2017 07:39:09 GMT

Hi,

I cannot get table keys via the RTTS technique. I use following code:

    DATA: the_table TYPE REF TO data.
    CREATE DATA the_table TYPE TABLE OF ('MARA').
    DATA typedescription TYPE REF TO cl_abap_tabledescr.
    typedescription ?= cl_abap_tabledescr=>describe_by_data_ref( the_table ).
    DATA keys TYPE abap_table_keydescr_tab.
    keys = typedescription->get_keys( ).

It always returns full list of fields, not only primary key, which I don't want.

I also tried the detection of keys from static internal table, but got the same result.

DATA: itab LIKE mara OCCURS 0 WITH HEADER LINE,
      lt_tabdescr     TYPE abap_keydescr_tab,
      ref_table_descr TYPE REF TO cl_abap_tabledescr.

ref_table_descr ?=  cl_abap_typedescr=>describe_by_data( itab[] ).
lt_tabdescr[] = ref_table_descr->key[].<br>

Detecting the key fields via describe_by_name( ) doesn't work either.

Any suggestions? System release is SAP ECC 7.40 SP09

Re: Getting database table keys via RTTS

Sandra_Rossi — Sun, 30 Jul 2017 08:00:49 GMT

You are confusing the primary key of the database table MARA, and the primary key of the internal table, which are completely different.

In your case, you have created a standard internal table with a default primary key (because you have not defined anything), which is made of all initial fields of the structure (MARA) up to the first non-character-type field (excluded).

If you want specific key fields, use DATA ... TABLE OF ... WITH [NON-]UNIQUE KEY field1 field2, or CREATE DATA ... TABLE OF ... WITH [NON-]UNIQUE KEY (dynamic list of fields).

For more information, refer to the ABAP documentation.

PS: please forget the obsolete notations OCCURS and WITH HEADER LINE.

Re: Getting database table keys via RTTS

Astashonok — Mon, 07 Aug 2017 09:55:43 GMT

Okkay, got it. But how to get key fields of dictionary transparent table?

Re: Getting database table keys via RTTS

pokrakam — Mon, 07 Aug 2017 11:19:01 GMT

I don't know the FM off the top of my head, but you can query table DD03L to get the key fields of a DB table.

PS. Adding this as a comment because Sandra technically provided the answer to your question as you asked it.

Re: Getting database table keys via RTTS

Astashonok — Mon, 07 Aug 2017 11:52:56 GMT

I know that FM, it's GET_KEY_FIELDS_OF_TABLE. I'm begging for pure RTTS solution.

Re: Getting database table keys via RTTS

retired_member — Mon, 07 Aug 2017 12:00:27 GMT

There is a method GET_DDIC_FIELD_LIST in CL_ABAP_STRUCTDESCR.

Re: Getting database table keys via RTTS

Astashonok — Wed, 11 Oct 2017 13:09:18 GMT

Nope. Just tested and GET_DDIC_FIELD_LIST always returns ALL fields, not only key ones. Maybe there is some trick?

Re: Getting database table keys via RTTS

Sandra_Rossi — Wed, 07 Mar 2018 19:52:27 GMT

Use DD03L as Mike said. RTTS doesn't need to know anything about keys/indexes of the database, as RTTS is only the dynamic part of the ABAP typing system.

Re: Getting database table keys via RTTS

Tomas_Buryanek — Thu, 29 Mar 2018 08:59:18 GMT

Filter returning table and you will get just key fields 🙂

DELETE lt_field_list WHERE keyflag <> 'X'.

Re: Getting database table keys via RTTS

Astashonok — Thu, 29 Mar 2018 15:59:20 GMT

You should put that as answer 🙂

Re: Getting database table keys via RTTS

Tomas_Buryanek — Tue, 03 Apr 2018 06:40:37 GMT

Well, as suggested by horst.keller in comments, you can use method get_ddic_field_list of class CL_ABAP_STRUCTDESCR.

And filter its returning table by KEYFLAG field value 🙂 For example:

DELETE lt_field_list WHERE keyflag <> 'X'.