Append two structures in an internal table.

hi,
if i join two tables by innerjoining will it effect the performance?If such,how i can join these with better performance?can i get the data from different tables in a single internal table by appending different structures in this case?Please answer me.

If inner Join has a performance issue the best thing u can do is...
Create 3 int tables. "This is to avoid 'INTO CORRESPONDING FIELDS' select query which will affect performance.
itab1 with the structure of table1
itab2 with the structure of table2
itab3 with the structure of table1 & table2
Select from 1st table into itab1.
if itab1 is not initial.
select from table 2 into itab2 for all entries in itab1 where field = itab1-field.
sort itab2 by field. "For binary search
loop itab1.
move-corresponding itab1 to itab3.
read itab2 with key field = itab1-field binary search.
move-corresponding itab2 to itab3.
append itab3.
endloop.
Regards
Sathar
Edited by: Sathar RA on Sep 8, 2008 9:10 AM

Similar Messages

Create object/structure like dynamic internal table

Hi,
We have created dynamic internal table with some fields.
for the above how to create structure or internal table like dynamic internal table structure .
Scenario: internal table itab1 ( with header line) have 5 fields.
Based on some of the conditions in layout of the report.
we have to create dynamic internal table.
field-symbols: <FS> type standard table.
we are able to create dynamic internal table with 3 fields
with assignment <fs> = itab1[]
the columns are not appearing but data appearing in next column.
how to solve this one
Thanks
Ramesh

Hi Ramesh,
I hope this code works...
report yup_alv_datbase                         .
*-Display Database table contents in ALV Grid Format
>********************************************************************
This report displays data from SAP tables, views (like SE16)        *
FM : REUSE_ALV_GRID_DISPLAY                                         *
tables:
dd02l,                               " SAP tables
dd03l.                               " Table Fields
type-pools: slis.                      " ALV Global Types
selection-screen :
begin of line, comment 1(35) v_1 for field p_table.         "#EC NEEDED
parameters p_table like dd03l-tabname obligatory memory id dtb.
selection-screen end of line.
selection-screen :
begin of line, comment 1(35) v_2 for field p_max.           "#EC NEEDED
parameters p_max(2) type n default '20' obligatory.
selection-screen end of line.
at selection-screen.
select single * from dd02l where tabname = p_table
                               and as4local = 'A'
                               and as4vers = '0000'.
if sy-subrc ne 0.
Table & is not active in the Dictionary
    message e402(mo) with p_table.
elseif dd02l-tabclass = 'INTTAB'.
& is a structure, not a table
    message e403(mo) with p_table.
endif.
initialization.
v_1 = 'Table'.
v_2 = 'Maximum of records'.
start-of-selection.
perform f_display_data.
     Form F_DISPLAY_DATA
form f_display_data.
Macro definition
define m_sort.
    add 1 to ls_sort-spos.
    ls_sort-fieldname = &1.
    ls_sort-up = 'X'.
    append ls_sort to lt_sort.
end-of-definition.
data:
    l_long type i,
    lp_struct   type ref to data,
    lp_table    type ref to data,      " Pointer to dynamic table
    of_sdescr   type ref to cl_abap_structdescr,
    ls_lvc_cat type lvc_s_fcat,
    lt_lvc_cat type lvc_t_fcat,       " Field catalog
    ls_fieldcat type slis_fieldcat_alv,
    lt_fieldcat type slis_t_fieldcat_alv, " Field catalog
    ls_layout   type slis_layout_alv,
    lt_sort     type slis_t_sortinfo_alv, " Sort table
    ls_sort     type slis_sortinfo_alv.
field-symbols :
    <fieldcat>   type slis_fieldcat_alv,
    <lt_data>    type table,           " Data to display
    <fs>         type any,
    <components> type abap_compdescr.
Dynamic creation of a structure
create data lp_struct type (p_table).
assign lp_struct->* to <fs>.
Fields Structure
of_sdescr ?= cl_abap_typedescr=>describe_by_data( <fs> ).
loop at of_sdescr->components assigning <components>.
Field MANDT not displayed
    if sy-tabix = 1 and <components>-name = 'MANDT'.
      continue.                        " Next loop
    endif.
Build Fieldcatalog
    ls_lvc_cat-fieldname = <components>-name.
    ls_lvc_cat-ref_table = p_table.
    append ls_lvc_cat to lt_lvc_cat.
Build Fieldcatalog
    ls_fieldcat-fieldname = <components>-name.
    ls_fieldcat-ref_tabname = p_table.
    append ls_fieldcat to lt_fieldcat.
endloop.
Create internal table
call method cl_alv_table_create=>create_dynamic_table
    exporting it_fieldcatalog = lt_lvc_cat
    importing ep_table = lp_table.
assign lp_table->* to <lt_data>.
Read data
select * from (p_table) up to p_max rows
    into corresponding fields of table <lt_data>
   order by primary key.
if <lt_data>[] is initial.
No table entries found for specified key
    message i429(mo).
    exit.
endif.
Read key field to Build Sort Table
select * from dd03l where tabname = p_table
                        and fieldname <> '.INCLUDE'
                        and as4vers = '0000'
                        and as4local = 'A'
                      order by position.
    read table lt_fieldcat assigning <fieldcat>
                            with key fieldname = dd03l-fieldname.
    check sy-subrc eq 0.
    add dd03l-leng to l_long.
    if dd03l-keyflag = 'X'.
    Build Sort Table
      m_sort dd03l-fieldname.
      <fieldcat>-key = 'X'.
    elseif l_long > 150.
      <fieldcat>-tech = 'X'.
    endif.
endselect.
ls_layout-zebra = 'X'.
ls_layout-colwidth_optimize = 'X'.
call function 'REUSE_ALV_GRID_DISPLAY'
       exporting
            is_layout   = ls_layout
            it_fieldcat = lt_fieldcat
            it_sort     = lt_sort
       tables
            t_outtab    = <lt_data>.
endform.                               " F_DISPLAY_DATA
END OF PROGRAM Z_ALV_DYNAMIC_DATA *********************
Regards,
Sampath

Declare flat structure as a internal table

hi,
i wrote the following code to declare structure as a internal table ....
TYPES: BEGIN OF internalltdoclinks.
include structure CRMT_DOC_FLOW_DB_WRKT.
types: END OF internalltdoclinks.
DATA: it_table TYPE STANDARD TABLE OF internalltdoclinks,
wa_bkpf TYPE internalltdoclinks.
it give me error as CRMT_DOC_FLOW_DB_WRKT
"CRMT_DOC_FLOW_DB_WRKT" must be a flat structure. You cannot use internal tables,strings ,references ,or structure as a component.
THANKS.

Hi,
You can declare as below if you want to declare a internal table
DATA: LT_DATA TYPE TABLE OF CRMT_DOC_FLOW_DB_WRKT.
So that there would be any error.

Create a deep structure for dynamic internal table

Hi All,
I am creating a dynamic table using method cl_alv_table_create=>create_dynamic_table.
The normal structure gets created. but now I want to creat a Deep structure for having information of colors also for each column. So I want to add a COLTAB type LVC_T_SCOL for colors information .
How should I create this using above method?
Rgds,
Madhuri

I created a zcelltab structure as below. But while creating dynamic internal table, I received the error with
'Type "ZCELLTAB" is unknown 68 ZCELLTAB-CELLTAB
Here is the code.
DATA: BEGIN OF ZCELLTAB,
         CELLTAB LIKE LVC_S_STYL,
     END OF ZCELLTAB.
FIELD-SYMBOLS <T_CELLTAB> TYPE LVC_T_STYL.
DATA : LT_CELLTAB TYPE LVC_T_STYL.
DATA: WA_CELLTAB TYPE LINE OF LVC_T_STYL.
DATA: GT_FCAT1 TYPE LVC_T_FCAT,
           GW_FCAT1 TYPE LVC_S_FCAT,
            GT_FCAT2 TYPE LVC_T_FCAT,
            GW_FCAT2 TYPE LVC_S_FCAT.
After filling the FCAT1, I added the field in FCAT2 like below
GT_FCAT2[ ] = GT_FCAT1[ ].
G_TABIX = G_TABIX + 1.
GW_FCAT2-INTTYPE = 'C'.
MOVE G_TABIX TO GW_FCAT2-COL_POS.
GW_FCAT2-OUTPUTLEN = '10'.
GW_FCAT2-FIELDNAME = 'T_CELLTAB'.
GW_FCAT2-TABNAME = 'ZCELLTAB'.
GW_FCAT2-REF_FIELD = 'CELLTAB'.
GW_FCAT2-REF_TABLE = 'ZCELLTAB'.
APPEND GW_FCAT2 TO GT_FCAT2
CLEAR GW_FCAT2.
While calling the below method, the error with
CALL METHOD CL_ALV_TABLE_CREATE=>CREATE_DYNAMIC_TABLE
     EXPORTING
      IT_FIELDCATALOG = GT_FCAT2
    IMPORTING
      EP_TABLE        = GT_REQ.
ASSIGN GT_REQ->* TO <F_TAB>.
CREATE DATA GWA_REQ LIKE LINE OF <F_TAB>.
ASSIGN GWA_REQ->* TO <F_WA>.
LOOP AT ITAB.
ASSIGN COMPONENT 'MATNR' OF STRUCTURE <F_WA> TO <F_VAL>
<F_VAL> = ITAB-MATNR.
IF ITAB-MATNR IS INITIAL.
ASSIGN COMPONENT 'T_CELLTAB' OF STRUCTURE <F_WA> TO <T_CELLTAB>
        CLEAR WA_CELLTAB.
        WA_CELLTAB-FIELDNAME = 'MATNR'.
        WA_CELLTAB-STYLE = CL_GUI_ALV_GRID=>MC_STYLE_DISABLED.
        INSERT WA_CELLTAB INTO TABLE <T_CELLTAB>.
ENDIF.
APPEND <F_WA> TO <F_TAB>
ENDLOOP.
CALL METHOD GR_GRID->SET_TABLE_FOR_FIRST_DISPLAY
        EXPORTING
          I_CONSISTENCY_CHECK = G_CONSISTENCY_CHECK
          IT_TOOLBAR_EXCLUDING = G_EXCLUDE
          I_SAVE               = G_SAVE
       I_DEFAULT            = 'X'
          IS_LAYOUT            = G_LAYOUT
        CHANGING
          IT_OUTTAB            = <F_TAB>
          IT_FIELDCATALOG      = F_CAT1.
Please let me know where I was wrong.
Should I remove the T_CELLTAB as the field name is not mentioned in the structure 'ZCELLTAB'.
Thanks,
Kumar.
Edited by: venn e on May 7, 2010 4:10 PM

To create a deep structure for dynamic internal table.

Hello
My ALV has fields which are defined dynamically during execution.
so, i did it in the following way,
Declared Field symbolds, DREF and fieldcatalog as,
FIELD-SYMBOLS: <t_dyntable> TYPE STANDARD TABLE,
              <fs_dyntable>.
DATA:   dref_dyntab    TYPE REF TO data,
        dref_dynwa     TYPE REF TO data.
DATA: ts_fieldcatalog TYPE lvc_t_fcat.
DATA: wa_fieldcatalog TYPE lvc_s_fcat.
Updated Fieldcatalog dynamically as,
*function module to read segment structure
    CALL FUNCTION 'SEGMENT_READ'
      EXPORTING
        segmenttyp           = v_segment_name
      TABLES
        segmentstructure     = ts_seg_structure
      EXCEPTIONS
        no_authority         = 1
        segment_not_existing = 2
        OTHERS               = 3.
    IF sy-subrc <> 0.
      CASE sy-subrc.
        WHEN '1'.
          MESSAGE e024.
          STOP.
        WHEN '2'.
          MESSAGE e025 WITH v_segment_name.
          STOP.
        WHEN OTHERS.
          MESSAGE e023.
      ENDCASE.
    ENDIF.
*FETCH FIELDS FROM STRUCTURE OF SEGMENT AND CREATE FIELDCATALOG FOR
EACH FIELD OF SEGMENT (DYNAMIC FIELD CATALOG)
    LOOP AT ts_seg_structure INTO wa_seg_structure.
      ADD 1 TO v_counter.
      wa_fieldcatalog-fieldname = wa_seg_structure-fieldname.
      wa_fieldcatalog-col_pos   = v_counter.
      wa_fieldcatalog-ref_table = wa_seg_structure-segtyp.
      APPEND wa_fieldcatalog TO ts_fieldcatalog.
      CLEAR wa_fieldcatalog.
    ENDLOOP.
and generated dynamic internal table using fieldcatalog as,
*--Method to get the structure of table using fieldcatalog.
CALL METHOD cl_alv_table_create=>create_dynamic_table
    EXPORTING
      it_fieldcatalog = ts_fieldcatalog
    IMPORTING
*--Variable of type REF TO DATA.
      ep_table        = dref_dyntab.
IF sy-subrc <> 0.
    MESSAGE e023.
ENDIF.
*--Dynamic internal tables required when show segments selected
IF p_selseg IS NOT INITIAL.
    ASSIGN dref_dyntab->* TO <t_dyntable>.
*--Create dynamic work area and assign to FS
CREATE DATA dref_dynwa LIKE LINE OF <t_dyntable>.
    ASSIGN dref_dynwa->* TO <fs_dyntable>.
And then i populated this <t_dyntable> which is being passed as data-table to method
CL_GUI_ALV_GRID => SET_TABLE_FOR_FIRST_DISPLAY
for ALV grid Display along with above used filedcatalog ts_fieldcatalog.
Things are fine till here, but now i have the requirement to edit selected rows of the ALV display..
As you might be aware, we need a field
        TS_STYLEROW TYPE lvc_t_styl, (i.e, a field of type 'h' and we can say as an internal table inside an internal table or else as a deep structure)
in the output internal table <t_dyntable> to meet our requirement.
My issue is about declaring one such field of type 'h' in this dynamically created internal table ''<t_dyntable>".
I tried in the following way by adding one such field to fieldcatalog :
*Field for Styling
ADD 1 TO v_counter.
wa_fieldcatalog-fieldname   = 'TS_STYLEROW'.
wa_fieldcatalog-tabname     = 'TS_STYLE'.
wa_fieldcatalog-col_pos     = v_counter.
wa_fieldcatalog-no_out      = 'X'.
wa_fieldcatalog-inttype     = 'h'.      " I even mentioned this
APPEND wa_fieldcatalog TO ts_fieldcatalog.
CLEAR wa_fieldcatalog.
But this is creating a field of type 'C' in the table <t_dyntable> instead of what i was expecting
Guyz and respected,
Please advice me with the solution or ur ideas....
Note : The overall requirement is create a deep structure for dynamically generated internal table.
Your help is highly appreciated and unforgettable..!!!!!!!

hi,
Dynamic append
Dynamic internal table
Dynamic internal table
dynamic columns in ALV
Variant for dynamic selection
thanks

How to append a structure to a std table

I appended two fields to vbak but these are not reflecing in the program.,i.e in program syntax error is showing that no componenet exist.
Please help out.
Thank you
Bhanu

Hi
steps:
0)Append structures allow you to attach fields to a table without actually having to modify the table itself. You can use the fields in append structures in ABAP programs just as you would any other field in the table.
1)Click on the append structure tab and opt to create new
structure.
Append structures allow you to enhance tables by adding fields to them that are not part of the standard. With append structures; customers can add their own fields to any table or structure they want.
Append structures are created for use with a specific table. However, a table can have multiple append structures assigned to it
2)Customers can add their own fields to any table or structure they want.
The customer creates append structures in the customer namespace. The append structure is thus protected against overwriting during an upgrade. The fields in the append structure should also reside in the customer namespace, that is the field names should begin with ZZ or YY. This prevents name conflicts with fields inserted in the table by SAP
<b>Reward if usefull</b>

How to determine structure of an Internal table dynamically ?

Dear Friends,
On the selection screen.. I have a parameter to pass a structure (eg. E1MARAM ) in to program . Now the challenge is to create an internal table with the structure that is passed from the selection screen(here eg.E1MARAM)
Please help me out..

Hello,
I had a similar situation where i did not know what the table name would be or the structure name would and this is how i created it.
*--Data Declaration.
FIELD-SYMBOLS : <i_temp> TYPE ANY TABLE,
                  <wa_temp> TYPE ANY,
                  <fs_begru> TYPE ANY.
**Internal table for getting structure of table obtained at run-time
DATA: BEGIN OF nametab OCCURS 0.
          INCLUDE STRUCTURE dntab.
DATA: END OF nametab.
**Move the Class table name obtained at run-time
MOVE dynamic-tabname TO tabname.
**Calling function to get the structure of the table name passed as
**exporting parameter
CALL FUNCTION 'NAMETAB_GET'
       EXPORTING
            langu               = sy-langu
            tabname             = tabname
       TABLES
            nametab             = nametab
       EXCEPTIONS
            internal_error      = 1
            table_has_no_fields = 2
            table_not_activ     = 3
            no_texts_found      = 4
            OTHERS              = 5.
IF sy-subrc <> 0.
MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
        WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.
ENDIF.
**Populating fieldcatalog
LOOP AT nametab .
    ls_alv_cat-fieldname     = nametab-fieldname .
    ls_alv_cat-ref_table     = tabname.
    ls_alv_cat-ref_field     = nametab-fieldname .
    APPEND ls_alv_cat TO lt_alv_cat.
ENDLOOP.
**Method for getting the reference for the structure
CALL METHOD cl_alv_table_create=>create_dynamic_table
      EXPORTING it_fieldcatalog = lt_alv_cat
      IMPORTING ep_table = dref.
**Passing the reference of the structure to field-symbol of type table
ASSIGN dref->* TO <i_temp>.
REFRESH i_field.
**Getting detailed structure of table
CALL FUNCTION 'CRS_GET_DDIC_TABLE'
       EXPORTING
            i_tabname           = tabname
       TABLES
            to_nametab          = i_field
       EXCEPTIONS
            internal_error      = 1
            table_has_no_fields = 2
            table_not_active    = 3
            no_texts_found      = 4
            OTHERS              = 5.
IF sy-subrc <> 0.
MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
        WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.
ENDIF.
Once you have done this... remember that the program does not know which table is this... but once you have got the table name you can either get the data from the database or if its a structure then you can fill it on your own
SELECT *
         FROM (tabname)
         INTO CORRESPONDING FIELDS OF TABLE <i_temp>.
IF sy-subrc NE 0.
ENDIF.
SORT : i_begru,
         i_matnr.
**Selecting records,extracted from Class table that meet selection
**creiteria
LOOP AT <i_temp> ASSIGNING <wa_temp>.
**Assigning BEGRU field
    ASSIGN COMPONENT pos_begru OF STRUCTURE <wa_temp> TO <fs_begru>.
or if you know what could be the structure that might get used
FIELD-SYMBOLS : <fs_bapi_mara>   TYPE bapi_mara,
                 <fs_bapi_marax> TYPE bapi_marax,
                 <fs_bapi_marc>   TYPE bapi_marc,
                 <fs_bapi_marcx> TYPE bapi_marcx,
                 <fs_bapi_mpop>   TYPE bapi_mpop,
DATA : dref TYPE REF TO data.
declare like this and then
**BAPI_MARA
CREATE DATA dref TYPE bapi_mara.
ASSIGN dref->* TO <fs_bapi_mara>.
**BAPI_MARAX
CREATE DATA dref TYPE bapi_marax.
ASSIGN dref->* TO <fs_bapi_marax>.
**BAPI_MARC
CREATE DATA dref TYPE bapi_marc.
ASSIGN dref->* TO <fs_bapi_marc>.
Go on creating the required structures on the selection criteria match ... when case
Regards,
Shekhar Kulkarni

Two collect statement from internal table

Dear Experts,
I want populate values to two internal tables from a internal table.
can i use two collect statement for different internal table from a single internal table.
advise please.
Thanks in advance.
R.Rajendran

hi there....
well u can very well use this thing.....
use the two colect statements inside the loop which u will use to read the records of the input table.
hope it helps.
do reward if it does.

Appending a record in an internal table while debugging

Hi gurus,
i am trying to add one record in a internal table at run time in debugging mode. i am adding the same record which is already exist in that internal table to test for some scenarios.after adding adn once if i click save, all the data i have entered is going and only the document number staying there. cant we add a record in debugging. if so where did i do mistake. thanks in advance,
santosh.

hi
yes u can add records in internal table in debugging mode.
switch to the classical debugger . double click on the internal table and press append button.
then add the first field value and then press enter ...then double click on the parallel line below the next field which will take u to input the next field enter value and press on the pencil. u need not press save.
to append next line press append button again and append in similar way.
<REMOVED BY MODERATOR>
Edited by: Alvaro Tejada Galindo on Feb 21, 2008 5:37 PM

Append screen inserted row to internal table

Hi Experts,
I have created a program using table control. But after filling a row when i press enter the entire row getting blank.
So i need to append the last inserted row from table control to internal table so that when i press enter that row remains on screen.
Thanks & Regards
Ashutosh Katara

Hi,
try this code in PAI,
IF sy-ucomm = 'ENTER'.
if tabc-col1 is NOT INITIAL and
     tabc-col2 is NOT INITIAL and
    tabc-col3 is NOT INITIAL and
     tabc-col4 is NOT INITIAL.
    w_tab-field1 = tabc-col1.
    w_tab-field2 = tabc-col2.
    w_tab-field3 = tabc-col3.
    w_tab-field3 = tabc-col4.
   modify <itab> FROM <workarea> INDEX sy-tabix.
ENDIF.
ENDIF

Differences between standard structured sorted hashed internal tables.

can any one elobrate the differences among them with simple examples.
why hashed table serch is faster...what happens if list is not sorted...explain the scenarios best suitable ..when we go for what kinda tables...

<a href="http://www.sap-img.com/abap/what-are-different-types-of-internal-tables-and-their-usage.htm">refer this link for details</a>
<a href="http://www.geekinterview.com/question_details/1498">also refer this</a>
<a href="http://help.sap.com/saphelp_nw04/helpdata/en/fc/eb366d358411d1829f0000e829fbfe/content.htm">also this- SAP Help</a>
regards,
srinivas

Appending two internal tables

hello friends,
I have two internal tables of different structure.
i have filled those two internal tables using join statements.
But one field is common in both the tables, when i try to append both tables into another new internal table.
i cant get the value for the 2nd tables field.
EX.
vbeln is common in vbuk, vbup, vbap, vbak, likp, lips.
but its sale order number in vbak, vbap.
delivery document in likp,lips.
vbup has both sales order and delivery in the vbeln field.
so, i made a join to between vbak, vbup and lips to see the goods movement status in vbup.
for that the vbeln should be delievery number.
and in other table, i have added vbup and vbak and vbep to get the delievery status.
for that the vbeln should be sale order no.
when i append both the tables into the third internal table that has the structure of both internal tables.
i could not get the vbeln of the second table(sale order no) in the third table.
help me guys.
rewards for helpful solutions.

hello,
types:
begin of str,
vbeln like vbak-vbeln,
vkorg like vbak-vkorg,
vtweg like vbak-vtweg,
end of str.
types:
begin of st1,
lfstk like vbuk-vbeln,
end of st1.
types:
begin of st2,
vbeln like vbak-vbeln,
vkorg like vbak-vkorg,
vtweg like vbak-vtweg,
lfstk like vbuk-lfstk,
end of st2.
selection-screen: s_order for vbak-vbeln,
                          s_div for vbak-vtweg.
data: it type table of st with header line,
        it1 type table of st1 with header line,
        it2 type table of st2 with header line.
select vbeln vkorg vtweg from vbak into table it
where         vbeln in s_order and
                 vkorg in s_div.
select lfstk from vbuk into table it1 for all entries in it
      where vbeln = it-vbeln.
it2[] = it[].
append it1-lfstk into it2[].
or
move-corresponding it1 to it2.
" when i execute this code with a grid or list display, i m not able to get the values or entries for the 2nd table it1.
the it2 has the lfstk cloumn blank in the final display.
help me for a remedy.
rewards for useful suggestion.

Internal Table and Structures

Hi,
I am a beginer. I know how to create a structure and how to create an internal table using ABAP/4. My problem is, i don't understand where to use internal table and structure, also i find myself very confused about the explicit work areas.
Plese someone show me a program by explaining all of this clearly.

Hi
Internal tables are the core of ABAP. They are like soul of a body. For any program we use
internal tables extensively. We can use Internal tables like normal data base tables only, but the
basic difference is the memory allocated for internal tables is temporary. Once the program is
closed the memory allocated for internal tables will also be out of memory.
But while using the internal tables, there are many performance issues to be considered. i.e which
type of internal table to be used for the program..like standard internal table, hashed internal
table or sorted internal table etc..
Internal tables
Internal tables provide a means of taking data from a fixed structure and storing it in working memory in ABAP. The data is stored line by
line in memory, and each line has the same structure. In ABAP, internal tables fulfill the function of arrays. Since they are dynamic data
objects, they save the programmer the task of dynamic memory management in his or her programs. You should use internal tables
whenever you want to process a dataset with a fixed structure within a program. A particularly important use for internal tables is for
storing and formatting data from a database table within a program. They are also a good way of including very complicated data
structures in an ABAP program.
Like all elements in the ABAP type concept, internal tables can exist both as data types and as data objects A data type is the abstract
description of an internal table, either in a program or centrally in the ABAP Dictionary, that you use to create a concrete data object. The
data type is also an attribute of an existing data object.
Internal Tables as Data Types
Internal tables and structures are the two structured data types in ABAP. The data type of an internal table is fully specified by its line type,
key, and table type.
Line type
The line type of an internal table can be any data type. The data type of an internal table is normally a structure. Each component of the
structure is a column in the internal table. However, the line type may also be elementary or another internal table.
Key
The key identifies table rows. There are two kinds of key for internal tables - the standard key and a user-defined key. You can specify
whether the key should be UNIQUE or NON-UNIQUE. Internal tables with a unique key cannot contain duplicate entries. The uniqueness
depends on the table access method.
If a table has a structured line type, its default key consists of all of its non-numerical columns that are not references or themselves
internal tables. If a table has an elementary line type, the default key is the entire line. The default key of an internal table whose line type
is an internal table, the default key is empty.
The user-defined key can contain any columns of the internal table that are not references or themselves internal tables. Internal tables
with a user-defined key are called key tables. When you define the key, the sequence of the key fields is significant. You should remember
this, for example, if you intend to sort the table according to the key.
Table type
The table type determines how ABAP will access individual table entries. Internal tables can be divided into three types:
Standard tables have an internal linear index. From a particular size upwards, the indexes of internal tables are administered as trees. In
this case, the index administration overhead increases in logarithmic and not linear relation to the number of lines. The system can access
records either by using the table index or the key. The response time for key access is proportional to the number of entries in the table.
The key of a standard table is always non-unique. You cannot specify a unique key. This means that standard tables can always be filled
very quickly, since the system does not have to check whether there are already existing entries.
Sorted tables are always saved sorted by the key. They also have an internal index. The system can access records either by using the
table index or the key. The response time for key access is logarithmically proportional to the number of table entries, since the system
uses a binary search. The key of a sorted table can be either unique or non-unique. When you define the table, you must specify whether
the key is to be unique or not. Standard tables and sorted tables are known generically as index tables.
Hashed tables have no linear index. You can only access a hashed table using its key. The response time is independent of the number of
table entries, and is constant, since the system access the table entries using a hash algorithm. The key of a hashed table must be unique.
When you define the table, you must specify the key as UNIQUE.
Generic Internal Tables
Unlike other local data types in programs, you do not have to specify the data type of an internal table fully. Instead, you can specify a
generic construction, that is, the key or key and line type of an internal table data type may remain unspecified. You can use generic
internal tables to specify the types of field symbols and the interface parameters of procedures . You cannot use them to declare data
objects.
Internal Tables as Dynamic Data Objects
Data objects that are defined either with the data type of an internal table, or directly as an internal table, are always fully defined in
respect of their line type, key and access method. However, the number of lines is not fixed. Thus internal tables are dynamic data objects,
since they can contain any number of lines of a particular type. The only restriction on the number of lines an internal table may contain are
the limits of your system installation. The maximum memory that can be occupied by an internal table (including its internal administration)
is 2 gigabytes. A more realistic figure is up to 500 megabytes. An additional restriction for hashed tables is that they may not contain more
than 2 million entries. The line types of internal tables can be any ABAP data types - elementary, structured, or internal tables. The
individual lines of an internal table are called table lines or table entries. Each component of a structured line is called a column in the
internal table.
Choosing a Table Type
The table type (and particularly the access method) that you will use depends on how the typical internal table operations will be most
frequently executed.
Standard tables
This is the most appropriate type if you are going to address the individual table entries using the index. Index access is the quickest
possible access. You should fill a standard table by appending lines (ABAP APPEND statement), and read, modify and delete entries by
specifying the index (INDEX option with the relevant ABAP command). The access time for a standard table increases in a linear relationship
with the number of table entries. If you need key access, standard tables are particularly useful if you can fill and process the table in
separate steps. For example, you could fill the table by appending entries, and then sort it. If you use the binary search option with key
access, the response time is logarithmically proportional to the number of table entries.
Sorted tables
This is the most appropriate type if you need a table which is sorted as you fill it. You fill sorted tables using the INSERT statement. Entries
are inserted according to the sort sequence defined through the table key. Any illegal entries are recognized as soon as you try to add
them to the table. The response time for key access is logarithmically proportional to the number of table entries, since the system always
uses a binary search. Sorted tables are particularly useful for partially sequential processing in a LOOP if you specify the beginning of the
table key in the WHERE condition.
Hashed tables
This is the most appropriate type for any table where the main operation is key access. You cannot access a hashed table using its index.
The response time for key access remains constant, regardless of the number of table entries. Like database tables, hashed tables always
have a unique key. Hashed tables are useful if you want to construct and use an internal table which resembles a database table or for
processing large amounts of data.
Creating Internal Tables
Like other elements in the ABAP type concept, you can declare internal tables as abstract data
types in programs or in the ABAP Dictionary, and then use them to define data objects.
Alternatively, you can define them directly as data objects. When you create an internal table as a
data object, you should ensure that only the administration entry which belongs to an internal
table is declared statically. The minimum size of an internal table is 256 bytes. This is important if an
internal table occurs as a component of an aggregated data object, since even empty internal
tables within tables can lead to high memory usage. (In the next functional release, the size of the
table header for an initial table will be reduced to 8 bytes). Unlike all other ABAP data objects, you
do not have to specify the memory required for an internal table. Table rows are added to and
deleted from the table dynamically at runtime by the various statements for adding and deleting
records.
You can create internal tables in different types.
You can create standard internal table and then make it sort in side the program.
The same way you can change to hashed internal tables also.
There will be some performance issues with regard to standard internal tables/ hashed internal
tables/ sorted internal tables.
Internal table types
This section describes how to define internal tables locally in a program. You can also define internal tables globally as data types in the
ABAP Dictionary.
Like all local data types in programs , you define internal tables using the TYPES statement. If you do not refer to an existing table type
using the TYPE or LIKE addition, you can use the TYPES statement to construct a new local internal table in your program.
TYPES <t> TYPE|LIKE <tabkind> OF <linetype> [WITH <key>]
[INITIAL SIZE <n>].
After TYPE or LIKE, there is no reference to an existing data type. Instead, the type constructor occurs:
<tabkind> OF <linetype> [WITH <key>]
The type constructor defines the table type <tabkind>, the line type <linetype>, and the key <key> of the internal table <t>.
You can, if you wish, allocate an initial amount of memory to the internal table using the INITIAL SIZE addition.
Table type
You can specify the table type <tabkind> as follows:
Generic table types
INDEX TABLE
For creating a generic table type with index access.
ANY TABLE
For creating a fully-generic table type.
Data types defined using generic types can currently only be used for field symbols and for interface parameters in procedures . The generic
type INDEX TABLE includes standard tables and sorted tables. These are the two table types for which index access is allowed. You cannot
pass hashed tables to field symbols or interface parameters defined in this way. The generic type ANY TABLE can represent any table. You
can pass tables of all three types to field symbols and interface parameters defined in this way. However, these field symbols and
parameters will then only allow operations that are possible for all tables, that is, index operations are not allowed.
Fully-Specified Table Types
STANDARD TABLE or TABLE
For creating standard tables.
SORTED TABLE
For creating sorted tables.
HASHED TABLE
For creating hashed tables.
Fully-specified table types determine how the system will access the entries in the table in key operations. It uses a linear search for
standard tables, a binary search for sorted tables, and a search using a hash algorithm for hashed tables.
Line type
For the line type <linetype>, you can specify:
Any data type if you are using the TYPE addition. This can be a predefined ABAP type, a local type in the program, or a data type from the
ABAP Dictionary. If you specify any of the generic elementary types C, N, P, or X, any attributes that you fail to specify (field length, number
of decimal places) are automatically filled with the default values. You cannot specify any other generic types.
Any data object recognized within the program at that point if you are using the LIKE addition. The line type adopts the fully-specified data
type of the data object to which you refer. Except for within classes, you can still use the LIKE addition to refer to database tables and
structures in the ABAP Dictionary (for compatibility reasons).
All of the lines in the internal table have the fully-specified technical attributes of the specified data type.
Key
You can specify the key <key> of an internal table as follows:
[UNIQUE|NON-UNIQUE] KEY <col1> ... <col n>
In tables with a structured line type, all of the components <coli> belong to the key as long as they are not internal tables or references,
and do not contain internal tables or references. Key fields can be nested structures. The substructures are expanded component by
component when you access the table using the key. The system follows the sequence of the key fields.
[UNIQUE|NON-UNIQUE] KEY TABLE LINE
If a table has an elementary line type (C, D, F, I, N, P, T, X), you can define the entire line as the key. If you try this for a table whose line
type is itself a table, a syntax error occurs. If a table has a structured line type, it is possible to specify the entire line as the key. However,
you should remember that this is often not suitable.
[UNIQUE|NON-UNIQUE] DEFAULT KEY
This declares the fields of the default key as the key fields. If the table has a structured line type, the default key contains all non-numeric
columns of the internal table that are not and do not contain references or internal tables. If the table has an elementary line type, the
default key is the entire line. The default key of an internal table whose line type is an internal table, the default key is empty.
Specifying a key is optional. If you do not specify a key, the system defines a table type with an arbitrary key. You can only use this to
define the types of field symbols and the interface parameters of procedures . For exceptions, refer to Special Features of Standard Tables.
The optional additions UNIQUE or NON-UNIQUE determine whether the key is to be unique or non-unique, that is, whether the table can
accept duplicate entries. If you do not specify UNIQUE or NON-UNIQUE for the key, the table type is generic in this respect. As such, it can
only be used for specifying types. When you specify the table type simultaneously, you must note the following restrictions:
You cannot use the UNIQUE addition for standard tables. The system always generates the NON-UNIQUE addition automatically.
You must always specify the UNIQUE option when you create a hashed table.
Initial Memory Requirement
You can specify the initial amount of main memory assigned to an internal table object when you define the data type using the following
addition:
INITIAL SIZE <n>
This size does not belong to the data type of the internal table, and does not affect the type check. You can use the above addition to
reserve memory space for <n> table lines when you declare the table object.
When this initial area is full, the system makes twice as much extra space available up to a limit of 8KB. Further memory areas of 12KB each
are then allocated.
You can usually leave it to the system to work out the initial memory requirement. The first time you fill the table, little memory is used. The
space occupied, depending on the line width, is 16 <= <n> <= 100.
It only makes sense to specify a concrete value of <n> if you can specify a precise number of table entries when you create the table and
need to allocate exactly that amount of memory (exception: Appending table lines to ranked lists). This can be particularly important for
deep-structured internal tables where the inner table only has a few entries (less than 5, for example).
To avoid excessive requests for memory, large values of <n> are treated as follows: The largest possible value of <n> is 8KB divided by the
length of the line. If you specify a larger value of <n>, the system calculates a new value so that n times the line width is around 12KB.
Examples
TYPES: BEGIN OF LINE,
COLUMN1 TYPE I,
COLUMN2 TYPE I,
COLUMN3 TYPE I,
END OF LINE.
TYPES ITAB TYPE SORTED TABLE OF LINE WITH UNIQUE KEY COLUMN1.
The program defines a table type ITAB. It is a sorted table, with line type of the structure LINE and a unique key of the component
COLUMN1.
TYPES VECTOR TYPE HASHED TABLE OF I WITH UNIQUE KEY TABLE LINE.
TYPES: BEGIN OF LINE,
COLUMN1 TYPE I,
COLUMN2 TYPE I,
COLUMN3 TYPE I,
END OF LINE.
TYPES ITAB TYPE SORTED TABLE OF LINE WITH UNIQUE KEY COLUMN1.
TYPES: BEGIN OF DEEPLINE,
FIELD TYPE C,
TABLE1 TYPE VECTOR,
TABLE2 TYPE ITAB,
END OF DEEPLINE.
TYPES DEEPTABLE TYPE STANDARD TABLE OF DEEPLINE
WITH DEFAULT KEY.
The program defines a table type VECTOR with type hashed table, the elementary line type I and a unique key of the entire table line. The
second table type is the same as in the previous example. The structure DEEPLINE contains the internal table as a component. The table
type DEEPTABLE has the line type DEEPLINE. Therefore, the elements of this internal table are themselves internal tables. The key is the
default key - in this case the column FIELD. The key is non-unique, since the table is a standard table.
Internal table objects
Internal tables are dynamic variable data objects. Like all variables, you declare them using the DATA statement. You can also declare static
internal tables in procedures using the STATICS statement, and static internal tables in classes using the CLASS-DATA statement. This
description is restricted to the DATA statement. However, it applies equally to the STATICS and CLASS-DATA statements.
Reference to Declared Internal Table Types
Like all other data objects, you can declare internal table objects using the LIKE or TYPE addition of the DATA statement.
DATA <itab> TYPE <type>|LIKE <obj> [WITH HEADER LINE].
Here, the LIKE addition refers to an existing table object in the same program. The TYPE addition can refer to an internal type in the
program declared using the TYPES statement, or a table type in the ABAP Dictionary.
You must ensure that you only refer to tables that are fully typed. Referring to generic table types (ANY TABLE, INDEX TABLE) or not
specifying the key fully is not allowed (for exceptions, refer to Special Features of Standard Tables).
The optional addition WITH HEADER line declares an extra data object with the same name and line type as the internal table. This data
object is known as the header line of the internal table. You use it as a work area when working with the internal table (see Using the
Header Line as a Work Area). When you use internal tables with header lines, you must remember that the header line and the body of the
table have the same name. If you have an internal table with header line and you want to address the body of the table, you must indicate
this by placing brackets after the table name (<itab>[]). Otherwise, ABAP interprets the name as the name of the header line and not of the
body of the table. You can avoid this potential confusion by using internal tables without header lines. In particular, internal tables nested
in structures or other internal tables must not have a header line, since this can lead to ambiguous expressions.
TYPES VECTOR TYPE SORTED TABLE OF I WITH UNIQUE KEY TABLE LINE.
DATA: ITAB TYPE VECTOR,
JTAB LIKE ITAB WITH HEADER LINE.
MOVE ITAB TO JTAB. <- Syntax error!
MOVE ITAB TO JTAB[].
The table object ITAB is created with reference to the table type VECTOR. The table object JTAB has the same data type as ITAB. JTAB also
has a header line. In the first MOVE statement, JTAB addresses the header line. Since this has the data type I, and the table type of ITAB
cannot be converted into an elementary type, the MOVE statement causes a syntax error. The second MOVE statement is correct, since
both operands are table objects.
Declaring New Internal Tables
You can use the DATA statement to construct new internal tables as well as using the LIKE or TYPE addition to refer to existing types or
objects. The table type that you construct does not exist in its own right; instead, it is only an attribute of the table object. You can refer to
it using the LIKE addition, but not using TYPE. The syntax for constructing a table object in the DATA statement is similar to that for defining
a table type in the TYPES statement.
DATA <itab> TYPE|LIKE <tabkind> OF <linetype> WITH <key>
[INITIAL SIZE <n>]
[WITH HEADER LINE].
As when you define a table type , the type constructor
<tabkind> OF <linetype> WITH <key>
defines the table type <tabkind>, the line type <linekind>, and the key <key> of the internal table <itab>. Since the technical attributes of
data objects are always fully specified, the table must be fully specified in the DATA statement. You cannot create generic table types (ANY
TABLE, INDEX TABLE), only fully-typed tables (STANDARD TABLE, SORTED TABLE, HASHED TABLE). You must also specify the key and whether
it is to be unique (for exceptions, refer to Special Features of Standard Tables).
As in the TYPES statement, you can, if you wish, allocate an initial amount of memory to the internal table using the INITIAL SIZE addition.
You can create an internal table with a header line using the WITH HEADER LINE addition. The header line is created under the same
conditions as apply when you refer to an existing table type.
DATA ITAB TYPE HASHED TABLE OF SPFLI
WITH UNIQUE KEY CARRID CONNID.
The table object ITAB has the type hashed table, a line type corresponding to the flat structure SPFLI from the ABAP Dictionary, and a
unique key with the key fields CARRID and CONNID. The internal table ITAB can be regarded as an internal template for the database table
SPFLI. It is therefore particularly suitable for working with data from this database table as long as you only access it using the key.

Grouping of two rows of internal table

Hi all,
I am having a requirement in which I want to group two rows of an internal table and assign a pointer to the two rows.
This pointer variable will then be passed to ALV.
Help reqd.
regards.

Hi Gaurav,
Hope the below code helps:
TYPES :BEGIN OF TY_ITAB2,
DATA(400),
END OF TY_ITAB2.
DATA: ITAB3 TYPE TY_ITAB2 OCCURS 0 WITH HEADER LINE
Loop at itab1.
ITAB3-DATA = ITAB1-LABEL.
APPEND ITAB3.
ITAB3-DATA = ITAB1-MATNR.
APPEND ITAB3.
endloop.
or
You can create a deep internal table. You can declare one Column as an internal table and store the NOTES in that Internal table for each row.
http://help.sap.com/saphelp_nw04/helpdata/en/fc/eb366d358411d1829f0000e829fbfe/content.htm
you can check the example in the link
Kindly Reward Points If You Find The Reply Helpful.
Cheers,
Chaitanya.

How to get the NameTab Structure(X031L) for Dynamic internal table?

when we pass standard table to the FM 'DD_GET_NAMETAB' we will get the
nametab structure(x031l), like this i want to get the same structure for
dynamic internal table . how can I achieve this
please help me...

Hi,
try this method
REPORT zmaschl_create_data_dynamic .
TYPE-POOLS: slis.
DATA: it_fcat TYPE slis_t_fieldcat_alv,
      is_fcat LIKE LINE OF it_fcat.
DATA: it_fieldcat TYPE lvc_t_fcat,
      is_fieldcat LIKE LINE OF it_fieldcat.
DATA: new_table TYPE REF TO data.
DATA: new_line TYPE REF TO data.
FIELD-SYMBOLS: <l_table> TYPE ANY TABLE,
               <l_line> TYPE ANY,
               <l_field> TYPE ANY.
Build fieldcat
CALL FUNCTION 'REUSE_ALV_FIELDCATALOG_MERGE'       EXPORTING           i_structure_name = 'SYST'       CHANGING           ct_fieldcat      = it_fcat[].   LOOP AT it_fcat INTO is_fcat WHERE NOT reptext_ddic IS initial.        MOVE-CORRESPONDING is_fcat TO is_fieldcat.        is_fieldcat-fieldname = is_fcat-fieldname.        is_fieldcat-ref_field = is_fcat-fieldname.        is_fieldcat-ref_table = is_fcat-ref_tabname.        APPEND is_fieldcat TO it_fieldcat.   ENDLOOP.
Create a new Table
CALL METHOD cl_alv_table_create=>create_dynamic_table       EXPORTING        it_fieldcatalog = it_fieldcat       IMPORTING        ep_table        = new_table.
Create a new Line with the same structure of the table.
ASSIGN new_table->* TO <l_table>.CREATE DATA new_line LIKE LINE OF <l_table>.ASSIGN new_line->* TO <l_line>.
Test it...
   DO 30 TIMES.
      ASSIGN COMPONENT 'SUBRC' OF STRUCTURE <l_line> TO <l_field>.
      <l_field> = sy-index.
      INSERT <l_line> INTO TABLE <l_table>.
   ENDDO.
   LOOP AT <l_table> ASSIGNING <l_line>.
      ASSIGN COMPONENT 'SUBRC' OF STRUCTURE <l_line> TO <l_field>.
      WRITE <l_field>.
   ENDLOOP.

Append two structures in an internal table.

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