All tables may be listed with t-code SE16 and table DD02L. But how can that list be accessed programmatically?
It is rarely a good idea to access the database tables directly since you will have to deal with all kinds of technicalities you probably don't even know about - active / inactive versions, for example. You will also bypass all security and authorization checks, which might be irrelevant to you personally, but is undesirable in general. To get a list of tables, you can use the function module RPY_TABLE_SELECT. This function module will take care of the version handling and provide the description in the language of your choice as well.
Improved Alex code in some way and put it as an option:
SELECT tabname
FROM DD02L
INTO TABLE #DATA(itab)
WHERE TABCLASS = 'TRANSP'.
LOOP AT itab ASSIGNING FIELD-SYMBOL(<FS>).
WRITE:/ <FS>.
ENDLOOP.
Several things were refined: incline declarations were utilized, field-symbols added, SELECT * and WHERE IN were omitted and so on. Also tables in SAP have only TRANSP class, INTTAB class belongs to structures.
Note: the sample is functional since ABAP 7.40, SP08.
An ongoing search resulted in the following snippet:
DATA ITAB TYPE TABLE OF DD02L.
SELECT * FROM DD02L INTO TABLE ITAB WHERE TABCLASS IN ('TRANSP', 'INTTAB').
WRITE :SY-SUBRC .
DATA FS TYPE DD02L.
LOOP AT ITAB INTO FS.
WRITE:/ FS-TABNAME.
ENDLOOP.
Table description is given in table DD02T.
Related
I'm trying to add data from a internal table to a custom one.
DATA: BEGIN OF TMP_CTRYGRP_T OCCURS 1000,
CTYGR TYPE /SAPSLL/CTYGR,
TEXT1 TYPE /SAPSLL/TEXT60,
END OF TMP_CTRYGRP_T.
SELECT ctygr, text1 FROM /SAPSLL/CTYGPT INTO TABLE #DATA(lt_countryGroupsTable)
LOOP AT lt_countryGroupsTable ASSIGNING FIELD-SYMBOL(<ls_countryGroups>).
APPEND <ls_countryGroups> TO TMP_CTRYGRP_T.
ENDLOOP.
Then I want to add the line in a custom Table Type ZZ_T_TAB
So I've tried to create a field-symbol of this table, creating an internal table from it, but none of the solutions I've tried was permitting me to add lines in that Custom table (even if the one in the program had the lines).
The problem I mainly encountered was:
are not mutually convertible in a Unicode program.
So my questions are:
Why does that error happen? Googling it didn't provide me an understandable answer
For the moment I'm using an internal table limited to 1000 rows. But I don't really know by advance the number of lines the search could provide. Is there any way to improve that?
How to add lines from any solution to my ZZ_T_TAB then? And afterwards how could I add other fields in the same table, for the rows already existing?
As some of you maybe understood, I'm quite a rookie in ABAP.
So if there's any useful link to understand all of that I would be happy if you can share it with me.
Why don't you directly select into the table?
Don't use OCCURS as it is declared obsolete and already forbidden in classes.
Declare your own structure as type and mark your custom internal table as TYPE STANDARD TABLE OF struct_type. This way, there will be no upper bounds
TYPES:
BEGIN OF struct_type,
CTYGR TYPE /SAPSLL/CTYGR,
TEXT1 TYPE /SAPSLL/TEXT60,
END OF struct_type.
DATA tmp_ctrygrp_t TYPE STANDARD TABLE OF struct_type WITH EMPTY KEY.
Why does that error happen? Googling it didn't provide me an
understandable answer
You cannot use APPEND with non-identical structures. You have to "convert" it before. Look up for the command MOVE-CORRESPODING in ABAP help (F1 on command in editor).
For the moment I'm using an internal table limited to 1000 rows. But I
don't really know by advance the number of lines the search could
provide. Is there any way to improve that?
Do not use OCCURS extension it is deprecated (as lausek wrote), old syntax.
How then to add lines from any solution to my ZZ_T_TAB ? And
afterwards how could I add other fields in the same table, for the
rows already existing?
You can modify a DB table various ways.:
1, Use UPDATE statement to directly update a field value.
2, Use MODIFY statement to modify field values from a (for example) pre-selected
structure.
Look up the UPDATE and MODIFY command in ABAP help, there are really helpful code examples.
I am new in ABAP and I have to modify these lines of code:
LOOP AT t_abc ASSIGNING <fs_abc> WHERE lgart = xyz.
g_abc-lkj = g_abc-lkj + <fs_abc>-abc.
ENDLOOP.
A coworker told me that I have to use a structure and not a field symbol.
How will be the syntax and why to use a structure in this case?
I have no idea why the co-worker wants that you use a structure in this case, because using a field symbol while looping is usually more performant. The reason could be that you are doing some kind of a novice training and he wants you to learn different syntax variants.
Using a structure while looping would like this
LOOP AT t_abc INTO DATA(ls_abc)
WHERE lgart = xyz.
g_abc-lkj = g_abc-lkj + ls_abc-abc.
ENDLOOP.
Your code is correct, because Field symbol functions almost the same as a structure.
For Field symbol
Field symbol is a pointer,
so there is no data copy action for field symbol, and the performance is better
Well if we changed the value via field symbol, the internal table get changed also
For Structure
Structure is a copy of the data, so there is a data copy action, and the performance is bad if the data row is bigger than 200 bytes (based on the SAP ABAP programming guide for performance)
If changed the data in the structure, the original internal table remains the same because there are 2 copies of the data in memory
Can someone simply explain me what happen in field symbols ABAP?
I'm glad if someone can explain the concept and how does it related to inheritance and how does it increasing the performance.
Field Symbols can be said to be pointers. Means, if You assign anything to a fields-symbol, the symbol is strong coupled ( linked ) to the variable, and any change to the fieldsymbol will change the variable immediately. In terms of performance, it comes to use, if You loop over an internal table. Instead of looping into a structure, You can loop into a fieldsymbol. If modifications to the internal table are made, then You can directly modify the fieldsymbol. Then You can get rid of the "modify" instruction,which is used in order to map the changes of the structure back to the corresponding line of the internal table.
"Read Table assigning" also serves the same purpose, like looping into a field-symbol.
Field-Symbol are more recommended then using a "workarea" ( when modifying ) , but references are the thing to go for now. They work almost similar to fieldsymbols.
Could I clarify it for You ?
Field-symbols in ABAP works as pointers in C++.
It has a lot of benefits:
Do not create extra-variables.
You can create a type ANY field-symbol, so you can point to any variable/table type memory space.
...
I hope these lines would be helpful.
Let's have a look at it when it comes to coding. Additionally i would like to throw in data references.
* The 'classic' way. Not recommended though.
LOOP AT lt_data INTO DATA(ls_data).
ls_data-value += 10.
MODIFY TABLE lt_data FROM ls_data.
ENDLOOP.
* Field symbols
LOOP AT lt_data ASSIGNING FIELD-SYMBOL(<fs_data>).
<fs_data>-value += 10.
ENDLOOP.
* Data references
LOOP AT lt_data REFERENCE INTO DATA(lr_data).
lr_data->value += 10.
ENDLOOP.
I personally prefer data references, because they go hand in hand with the OO approach. I have to admit that field symbols are slightly in front when it comes to performance.
The last two should be preferred when talking about modifying. The first example has an additional copy of data which decreases overall performance.
I'm pretty new to this. I'm currently studying abap for my job and I have a problem that I can't seem to work out. How would I go about creating a Function Module that takes any kind of internal table and write it to the screen? I'm looking for a very generic solution that can work with any kind of internal table as input.
This is the exact reason SAP has developed ALV (ABAP List Viewer).
One of the shortest way to display any (non-nested) table is the following.
DATA: go_alv TYPE REF TO cl_salv_table.
CALL METHOD cl_salv_table=>factory
IMPORTING
r_salv_table = go_alv
CHANGING
t_table = itab.
go_alv->display( ).
This would be the simplest way for a table whose line type is only flat data objects, taken from page 33 of This SAP Development Guide.
FIELD-SYMBOLS: <row> TYPE ANY,
<comp> TYPE ANY.
LOOP AT itab INTO <row>.
DO.
ASSIGN COMPONENT sy-index OF STRUCTURE <row> TO <wa_comp>.
IF sy-subrc <> 0.
SKIP.
EXIT.
ENDIF.
WRITE <wa_comp>.
ENDDO.
ENDLOOP.
A more robust way would be to use introspection containing Run-Time Type Services, a set of classes that let you introspect the details of a data object. This would give you the details mentioned by vwegert. An even better option would be to put it in an ALV grid.
It is possible, but you have to think about a lot of stuff:
column widths, dynamically sizing columns
currency fields / fields with units
date formatting in a multi-lingual environment
tables may contain arbitrary data, including nested tables
All things considered, this is not a trivial task. This is best left to the existing components.
I am a newbie to ABAP (3 days experience) and I am currently on a task to write reports using ABAP code. It is like moving some data from a specific SAP database to a Business Intelligence staging area.
So the core difficulty is that some data on the SAP server is in the format of dictionary structures (FMOIX, FMCOX, etc.) and I need to move these data into internal tables during program runtime. I was told that OPENSQL would not work in this case.
If you still do not get what I mean, I can suggest several ways, actually given by my supervisor. First is to use GET event, say
GET FMOIX.
IF FMOIX-zhdlt > From_dat and FMOIX-zhdlt < to_dat.
Append FMOIX to itab.
ENDIF.
The thing is that I am still not very clear about this GET event. Is it just a event handler thing, or can it loop through data records?
What I googled for more than two days give me something like
LOOP at FMOIX.
MOVE FMOIX to itab.
ENDLOOP.
So what are the ways to move transactional structure like FMOIX into internal tables, say the internal table name is ITAB?
Your answer would be greatly appreciated. Though I have time, I am totally new.
Thanks a lot.
If your supervisor is suggesting that you use the GET event, it means that your program is (or should be) using a logical database - in this case probably FMF or FMF_BCS.
Doing GET FMOIX reads a set of fields defined in the logical database (as a node). Underneath your GET statement, you can use FMOIX as a structure, e.g. WRITE FMOIX-field1. The program will (implicitly, it's not explicity defined in the code like a LOOP...ENDLOOP is) loop through all the rows returned according to your selection criteria. You should be able to use MOVE-CORRESPONDING to move the contents of each row into a proper structure, and then APPEND that structure to your itab.
Quick link on GET in ABAPDocu
Note: this answer is a bit of a guess, since I've only used a logical database once, and the documentation is a little thin on the ground compared to the volumes out there about standard SELECTs and internal tables.
You can create your internal table in type of that structure such as:
data: itab like table of fmoix with header line.
And you can use this internal table to fill up wherever you are using your select codes.
Such as:
select * from ____
into corresponding fields of itab
where zhdlt gt from_dat
and zhdlt lt to_dat.
I'm not sure this is what you are looking for but I can tell you creating itab in type of that structure can be filled up with all corresponding datas that coming from your select. You cant loop FMOIX because its not a table, its a structure. So is there any specific reason to hold your datas in structures?
Hope it was helpful.
Talha