Reading a field symbol whose structure is dynamic

Hi Experts,
I have used the concept of dynamic internal tables to select data from COSS/COSP for e.g.database tables.Field symbol of type " ANY TABLE" has been used to select data , as the dynamic structure is assigned directly to the field symbol.
To calculate the values of various fields I need to read the this field symbol for diferent line items , but I get a compilation error saying " Key not Found ". I understand that I am not able to read the field symbol because its structure is of type 'ANY TABLE' .How do I read this field symbol ?
The field symbol gets the structure of dynamic internal table as formed initially by using class concept.Is their any way in which I could get the structure of this field symbol or any other way to read it?
Thanks in advance.
Regards
Reetwika

Hi Ritwika,
Even if u use the concept if dynamic internal table, u can read the each of the field of ur structure,
if u know the name of the field.
for example:
MATNR being one of the field of internal table
field-symbols : <fs> type any.
loop at <fs_it> into <fs_wa>.
ASSIGN COMPONENT 'MATNR' OF STRUCTURE <fs_wa> to <fs_matnr>.
" in this case matnr field value will be assigned to the field symbol <fs_matnr>, so it can be used further.
endloop.
" do reply if still confused.
Rohit G
Edited by: Rohit Gaharwar on Aug 12, 2009 11:51 AM

Similar Messages

Field symbols to structures

when a run time error occurs using field symbols of structures to data objects corresponds to alignment.?
please explain with an example.

I think it would be better for you to explain what you are doing and what the runtime error is all about.
Because: 'field symbols of structures to data objects corresponds to alignment' doesn't ring a bell for any of us obviously.

Dynamic Field Symbols with Structures

Hello,
I am stuck on a piece of code and looking for some help. I am trying to figure out how to assign values in a structure of a dynamically defined field symbol to the structure inside another dynamically defined field symbol. Here is my code and some comments. Basically I am uploading data via a flatfile and placing it into a dynamically defined field symbol.
DATA:
lr_area     TYPE REF TO cl_sem_planarea_attributes,
lr_t_data   TYPE REF TO data,
lr_s_data   TYPE REF TO data,
lr_s_chas   TYPE REF TO data,
lr_s_kyfs   TYPE REF TO data.
FIELD-SYMBOLS:
<lt_data> TYPE STANDARD TABLE,
<ls_data> TYPE ANY,
<ls_chas> TYPE ANY,
<ls_kyfs> TYPE ANY.
DATA: ls_chasel TYPE upc_ys_chasel,
ls_charng TYPE upc_ys_charng.
FIELD-SYMBOLS:
<f> TYPE ANY,
<chas> TYPE TABLE,
<kyfs> TYPE ANY.
CALL METHOD cl_sem_planarea_attributes=>get_instance
EXPORTING       i_area      = i_area
RECEIVING       er_instance = lr_area.
CHECK sy-subrc = 0.
CREATE DATA lr_s_data TYPE (lr_area->typename_s_data).
ASSIGN lr_s_data->*   TO <ls_data>.
CREATE DATA lr_t_data TYPE (lr_area->typename_t_data).
ASSIGN lr_t_data->*   TO <lt_data>.
CREATE DATA lr_s_chas TYPE (lr_area->typename_s_chas).
ASSIGN lr_s_chas->*   TO <ls_chas>.
CREATE DATA lr_s_kyfs TYPE (lr_area->typename_s_kyfs).
ASSIGN lr_s_kyfs->*   TO <ls_kyfs>.
LOOP AT gt_file INTO ls_file.
CLEAR <ls_data>.
MOVE-CORRESPONDING ls_file TO <ls_kyfs>. " Map key figures
MOVE-CORRESPONDING ls_file TO <ls_chas>. " Map chars
*    MOVE-CORRESPONDING ls_file TO <ls_data>. " Map data
*        ASSIGN COMPONENT 'ls_chas' OF STRUCTURE <ls_Data> TO <chas> .
*        IF sy-subrc = 0.
**          <chas> = <ls_chas>.
*MOVE-CORRESPONDING <ls_chas> to <chas>.
*        ENDIF.
<chas> = <ls_chas>.
LOOP AT <chas> INTO ls_chasel.
READ TABLE ls_chasel-t_charng INTO ls_charng INDEX 1.
IF sy-subrc = 0 AND ls_charng-option = 'EQ'.
ASSIGN COMPONENT ls_chasel-chanm OF STRUCTURE <ls_chas> TO <ls_data>.
IF sy-subrc = 0.
<ls_data> = ls_charng-low.
ENDIF.
ENDIF.
ENDLOOP.
COLLECT <ls_data> INTO <lt_data>.
ENDLOOP.
Ls_chasel has 2 components:
Chanm (a char 30 which contains the component’s name)
T_CHARNG (a table with values for chanm)
Ls_data has 2 components:
S_chas (a structure with a list of components and values – same list as would have)
S_kyfs (a structure with a list of components and values – same list as would have)
Lt_data is a table of ls_data
I need to get the data in ls_chas into the ls_chas structure of ls_data and the ls_kyfs data into the ls_kyfs structure of ls_chas and append ls_chas to lt_data. Anything that is commented out is something I tried that didn't work. RIght now I get a dump at the 'loop at <chas> into ls_chasel' that the field symbol is not assigned.
Thanks for your help!

It looks like the the original poster didn't completely understand all he was doing. (This is why I always recommend getting an ABAP programmer in for what is, essentially, advanced ABAP programming, rather than someone "kind of familiar" with ABAP trying it - we're often available at very reasonable rates ).
It seems he's using ito_chasel to set the fixed values (which is in fact quite smart!). What isn't required, so far as I can tell without implementing, are any of the statements involving <ls_kyfs> or <ls_chas>.
The following should be sufficient (with the necessary declarations etc. - but really: omit <ls_kyfs> and <ls_chas> - I'm sure they're not needed and they confuse things).
" Go through the data from the flat file
LOOP AT gt_file INTO ls_file.
CLEAR <ls_data>.
" Transfer the characteristics
MOVE-CORRESPONDING ls_file TO <s_chas>.
" Transfer the key figure
MOVE-CORRESPONDING ls_file TO <s_kyfs>.
" Go through the fixed characteristic selections from the package
LOOP AT ito_chasel INTO ls_chasel.
    " We only care about the first value (if there is one).
    READ TABLE ls_chasel-s_charng INTO ls_charng INDEX 1.
    " Check there is a first value and that it is fixed
    CHECK sy-subrc IS INITIAL AND ls_charng EQ 'EQ'.
    " Get access to that characteristic
    FIELD-SYMBOLS <fixed_value> TYPE ANY.
    ASSIGN COMPONENT ls_chasel-chanm OF STRUCTURE <s_chas> TO <fixed_value>.
    " Make sure that it exists in the data structure
    CHECK sy-subrc IS INITIAL.
    " Set the value
    <fixed_value> = ls_charng-low.
ENDLOOP.
COLLECT <ls_data> INTO <lt_data>.
ENDLOOP.

Read line + field symbol

Hi expets.
I have some doubt related to Read Line, iknow it's use but it fails when i m using field symbol.
1->
Do w_lines times.
Read line sy-index field value <fs_customer>-name1.
enddo
Here it makes dump because i m using fied symbol. Its type is correct .
But when i use int. table or structure it's wrks fine
2-> when i try to hide a field sybmol it shows dump. what can i do?
actually in a loop i_customer assigning <fs_customer>
write: /<fs_customer>-name1..etc...
hide : <fs_customer>-kunnr.
here it makes dump when i hide
3-> Problem is-
I have two reports on same screen.1 for Customer and another for Vendor.
both have check boxes.
I want to read them from Screen output and for Customer name i have to get the Customer no. for the selected check box.
Same is with the venodr report n same screen.
wen slect Vendor name check box get vendor no.
My issue is that how i should read two reports on same screen for check boxes.
I mean i will make a DO ...ENDDO . and on it i will read for sy-line-1 times.
then hw i will separate that whetehr this read is for Customer or Vendor.
Do i need to set some flag and then hide that flag.
and supoose if Flag eq C at read then its custoer and as it will be V then its Vendor,
All teh Vendor report is Below thw Customer.
Please tell me the advantage of Field symbol over heaer lines of table./
thanks in Advance.

Loop to get the unselected checkbox
DO l_line_lockbx TIMES.
Read the lines on Screen -for LOCK BOX
    READ LINE sy-index FIELD VALUE g_check
                                                     <fs_lockbx>-name1 .
    IF sy-subrc EQ 0 .
If Check Box is not selected-Store in a separate table
    if g_check eq c_x.
    clear l_name_lockbx.
    move <fs_lockbx>-name1 to l_name_lockbx.
Read table to get the Detail when ceck box not selected
    read table i_lockbx with key name1 = l_name_lockbx
                                binary search
                                assigning <fs_lockbx>.
      IF sy-subrc EQ 0.
      MOVE : <fs_lockbx>-serial     TO <fs_rcvlad>-serial ,
                   <fs_lockbx>-rcvlad    TO <fs_rcvlad>-rcvlad ,
                   <fs_lockbx>-docnum TO <fs_rcvlad>-docnum .
      APPEND <fs_rcvlad> TO i_rcvlad.
      CLEAR :<fs_rcvlad> ,
                   <fs_lockbx> ,
                     g_check     .
     endif.            " IF sy-subrc EQ 0
    ENDIF.             " if g_check ne c_x.
ENDDO.               " DO l_line_lockbx TIMES.

Regarding reading a field symbols with a key

Hi
i have a scenario where i need to delete some duplicates from previous selection
i' m selecting some 1000 records from one table. now in my second selection i' m reading records from 1001 to 2000.
now i need to compare the last record(1000th) and compare the record with this second selection(1001 to 2000). in this scenario i' m using all feild symbols. here is the code
        SELECT * FROM (pa_tab)
               INTO TABLE <lt_dyntable>
               UP TO pa_ind ROWS
               WHERE (lt_conditions_temp).
initially <lt_dyntable> contains 1000 records
if lv_dbcnt GT 1000.
read table <lt_dyntable> assigning <ls_dyntable> with key
<ls_dyntable> = <ls_check>.-----ERROR
endif.
this i have written to get the last record.
      LOOP AT <lt_dyntable> assigning <ls_dyntable>.
      ENDLOOP.
i have stored the last record in this check. as the table <lt_dyntable> should be refreshed.
move <ls_dyntable> to <LS_CHECK>.
the code which i mentioned is giving me an error.
<ls_dyntable> TYPE ANY,
<ls_check> type any.
let me know where i' m doing the error.
Thanks & Regards,
T.Subhashini.

Hi,
I think it is looking for a field <ls_dyntable> in your internal table <lt_dyntable>
read table <lt_dyntable> assigning <ls_dyntable> with key
<b><ls_dyntable> = <ls_check>.-----</b>ERROR
Try this..
READ TABLE <lt_dyntable> assigning <ls_dyntable> INDEX 1.
IF <ls_dyntable> = <ls_check>.
ENDIF.
Thanks,
Naren

Read Dynamic Field Symbol

Hello ,
I have a field symbol where i am not aware of fields (Column Name) , i mean column names are Dynamic.
Problem is i need to read this field symbol value , how can i do it . It will always have 1 record
Example
Field Symbol looks something like this
<FS> Column Name dynamic -
>
A B C
Record
1 2 3
So now i have to refer to Second Column (i.e. is B in this case) , how should i do
What i tried .
1. <FS>-(Column Name in variable in brackets) - It doesnt work , Error Message unable to interpret the number B
2. <FS>[1] - Error out.

For a structured data object <s>, you can use the statement
<b>
ASSIGN COMPONENT <comp> OF STRUCTURE <s> TO <FS>.
</b>
to assign one of its components <comp> to the field symbol <FS>. You can specify the
component <comp> either as a literal or a variable. If <comp> is of type C or a structure which
has no internal tables as components, it specifies the name of the component. If <comp> has any
other elementary data type, it is converted to type I and specifies the number of the component.
In the assignment is successful, SY-SUBRC is set to 0. Otherwise, it returns 4.

Read Data from the dynamic Field Symbol with key ?

Dear All,
I've 2 dynamic internal tables in the form of field symbols.
Now,I want to loop the item field symbol, read the header field symbol content and then move the corresponding into a final field symbol.
How to read the field symbol with key ?
When I'm trying to give the key clause in the paranthesis it's giving a syntax error.
Any clues ?
FYI .....
* Get the Dynamic Field and Value for the Date/Year and convert it into Year value
LOOP AT <fs_t_son> ASSIGNING <wa_son>.
    ASSIGN COMPONENT gwa_znrows_def-fieldname OF STRUCTURE <wa_son> TO <fs_year>.
    IF sy-subrc = 0.
      CLEAR gv_string.
      MOVE <fs_year> TO gv_string.
      CLEAR gv_year.
      gv_year = gv_string.
      <fs_year> = gv_year.
    ELSE.
* When the Date/year Field is not in the Table then -->
* Get the Dynamic Field and Value
      ASSIGN COMPONENT gwa_znrows_def-kfldname OF STRUCTURE <wa_rson> TO <fs_value>.
* Populate field for Dynamic Where condition
      CLEAR gv_value.
      CONCATENATE '''' <fs_value> '''' INTO gv_value.
      CONCATENATE gwa_znrows_def-kfldname '=' gv_value INTO gt_where SEPARATED BY space.
      APPEND gt_where.
      CLEAR gt_where.
      READ TABLE <fs_t_rson> ASSIGNING <wa_rson> ( gt_where ). "Key clause
    ENDIF. " if sy-subrc = 0. "Assign
ENDLOOP.
Thanks & regards,
Deepu.K

TYPES: BEGIN OF line,
         col1 TYPE c,
         col2 TYPE c,
       END OF line.
DATA: wa TYPE line,
      itab TYPE HASHED TABLE OF line WITH UNIQUE KEY col1,
      key(4) TYPE c VALUE 'COL1'.
FIELD-SYMBOLS <fs> TYPE ANY TABLE.
ASSIGN itab TO <fs>.
READ TABLE <fs> WITH TABLE KEY (key) = 'X' INTO wa.
The internal table itab is assigned to the generic field symbol <fs>, after which it is possible to address the table key of the field symbol dynamically. However, the static address
READ TABLE <fs> WITH TABLE KEY col1 = 'X' INTO wa.
is not possible syntactically, since the field symbol does not adopt the key of table itab until runtime. In the program, the type specification ANY TABLE only indicates that <fs> is a table. If the type had been ANY (or no type had been specified at all), even the specific internal table statement READ TABLE <fs> would not have been possible from a syntax point of view.

How to read dynamic field symbol

hi all,
ASSIGN (tabname) TO <fs_tab>.
in above code i am passing dynamic table to fs_tab
can anyone tell me how can i read this field symbol........
in other words i want to read dynamic field symbols

Hi,
you could do without the field-symbols:
select from variable table
grtz,
Koen

Dynamic field symbol

Hello :i would like to ask one favor , how can i define a field symbol, that can recieve a dynamic variable
segment of code:
CALL METHOD cl_alv_table_create=>create_dynamic_table
    EXPORTING
      it_fieldcatalog = it_fldcat
    IMPORTING
      ep_table        = it_dynamic.
ASSIGN it_dynamic->* TO <dyn_table>.
CREATE DATA wa_dynamic LIKE line of <dyn_table>.
ASSIGN wa_dynamic->* TO <dyn_wa>. " this one 'wa_dynamic' i need to sent to <dyn_wa>
thanks a lot

HI
GOOD
Generic Type Specification
The following types allow you more freedom when using actual parameters. The data object only needs to have the selection of attributes specified.
Typing
Check for data object
No type specification
TYPE ANY
All types of data object are accepted. The field symbol adopts all of the attributes of the data object.
TYPE C, N, P, or X
Only data objects with type C, N, P, or X are accepted. The field symbol adopts the field length and DECIMALS specification (type P) of the data object.
TYPE TABLE
The system checks whether the data object is a standard internal table. This is a shortened form of TYPE STANDARD TABLE (see below).
TYPE ANY TABLE
The system checks whether the data object is an internal table. The field symbol inherits all of the attributes (line type, table type, key) from the data object.
TYPE INDEX TABLE
The system checks whether the data object is an index table (standard or sorted table). The field symbol inherits all of the attributes (line type, table type, key) from the data object.
TYPE STANDARD TABLE
The system checks whether the data object is a standard internal table. The field symbol inherits all of the remaining attributes (line type, key) from the data object.
TYPE SORTED TABLE
The system checks whether the actual parameter is a sorted internal table. The field symbol inherits all of the remaining attributes (line type, key) from the data object.
TYPE HASHED TABLE
The system checks whether the actual parameter is a hashed internal table. The field symbol inherits all of the remaining attributes (line type, key) from the data object.
If you specify a type generically, remember that the attributes inherited by the field symbol from the program are not statically recognizable in the program. You can, at most, address them dynamically.
TYPES: BEGIN OF line,
         col1 TYPE c,
         col2 TYPE c,
       END OF line.
DATA: wa TYPE line,
      itab TYPE HASHED TABLE OF line WITH UNIQUE KEY col1,
      key(4) TYPE c VALUE 'COL1'.
FIELD-SYMBOLS <fs> TYPE ANY TABLE.
ASSIGN itab TO <fs>.
READ TABLE <fs> WITH TABLE KEY (key) = 'X' INTO wa.
The internal table ITAB is assigned to the generic field symbol <FS>, after which it is possible to address the table key of the field symbol dynamically. However, the static address
READ TABLE <fs> WITH TABLE KEY col1 = 'X' INTO wa.
is not possible syntactically, since the field symbol does not adopt the key of table ITAB until runtime. In the program, the type specification ANY TABLE only indicates that <FS> is a table. If the type had been ANY (or no type had been specified at all), even the specific internal table statement READ TABLE <FS> would not have been possible.
If you adopt a structured type generically (a structure, or a table with structured line type), the individual components cannot be addressed in the program either statically or dynamically. In this case, you would have to work with further field symbols and the method of assigning structures component by component.
Specifying the Type Fully
When you use the following types, the technical attributes of the field symbols are fully specified. The technical attributes of the data objects must correspond to those of the field symbol.
Typing
Technical attributes of the field symbol
TYPE D, F, I, or T
The field symbol has the technical attributes of the predefined elementary type
TYPE <type>
The field symbol has the type <type>. This is a data type defined within the program using the TYPES statement, or a type from the ABAP Dictionary
TYPE REF TO <cif>|DATA
The field symbol is a reference variable for the class or interface <cif>, or for a data object.
TYPE LINE OF <itab>
The field symbol has the same type as a line of the internal table <itab> defined using a TYPES statement or defined in the ABAP Dictionary
LIKE <f>
The field symbol has the same type as an internal data object <f> or structure, or a database table from the ABAP Dictionary
When you use a field symbol that is fully typed, you can address its attributes statically in the program, since they are recognized in the source code. If you fully specify the type of a field symbol as a reference or structured data object, you can address it as you would the data object itself, once you have assigned an object to it. So, for example, you could address the components of a structure, loop through an internal table, or create an object with reference to a field symbol.
REPORT demo_field_symbols_type .
DATA: BEGIN OF line,
         col1(1) TYPE c,
         col2(1) TYPE c VALUE 'X',
       END OF line.
FIELD-SYMBOLS <fs> LIKE line.
ASSIGN line TO <fs>.
MOVE <fs>-col2 TO <fs>-col1.
The field symbol <FS> is fully typed as a structure, and you can address its components in the program.
Attaching a structure to a field symbol
The STRUCTURE addition forces a structured view of the data objects that you assign to a field symbol.
FIELD-SYMBOLS <FS> STRUCTURE <s> DEFAULT <f>.
The structure <s> is either a structured local data object in the program, or a flat structure from the ABAP Dictionary. <f> is a data object that must be assigned to the field symbol as a starting field. However, this assignment can be changed later using the ASSIGN statement.
When you assign a data object to the field symbol, the system only checks that it is at least as long as the structure. You can address the individual components of the field symbol. It has the same technical attributes as the structure <s>.
If <s> contains components with type I or F, you should remember the possible effects of alignment. When you assign a data object to a field symbol with a structure, the data object must have the same alignment, otherwise a runtime error may result. In such cases, you are advised to assign such data objects only to structured field symbols, which retain the same structure as the field symbol at least over the length of the structure.
The STRUCTURE is obsolete; you should no longer use it. Field symbols defined using the STRUCTURE addition are a mixture of typed field symbols and a utility for casting to either local or ABAP Dictionary data types. If you want to define the type of a field symbol, include the TYPE addition in a FIELD-SYMBOLS statement. If you want to use casting, include the CASTING addition in an ASSIGN statement.
Example using the obsolete STRUCTURE addition:
DATA: wa(10) VALUE '0123456789'.
DATA: BEGIN OF line1,
         col1(3),
         col2(2),
         col3(5),
      END OF line1.
DATA: BEGIN OF line2,
         col1(2),
         col2 LIKE sy-datum,
      END OF line2.
FIELD-SYMBOLS: <f1> STRUCTURE line1 DEFAULT wa,
               <f2> STRUCTURE line2 DEFAULT wa.
WRITE: / <f1>-col1, <f1>-col2, <f1>-col3,
       / <f2>-col1, <f2>-col2.
Example using the correct syntax (TYPE and CASTING):
DATA: wa(10) VALUE '0123456789'.
DATA: BEGIN OF line1,
         col1(3),
         col2(2),
         col3(5),
      END OF line1.
DATA: BEGIN OF line2,
         COL1(2),
         COL2 LIKE sy-datum,
      END OF line2.
FIELD-SYMBOLS: <f1> LIKE line1.
ASSIGN wa TO <f1> CASTING.
FIELD-SYMBOLS: <f2> LIKE line2.
ASSIGN wa TO <f2> CASTING.
WRITE: / <f1>-col1, <F1>-col2, <F1>-col3,
       / <f2>-col1, <F2>-col2.
In both cases, the list appears as follows:
012 34 56789
01 2345/67/89
This example declares two field symbols to which different structures are attached. The string WA is then assigned to each of them. The output shows that the field symbols assign the strings component by component according to the type of the components.
http://help.sap.com/saphelp_nw04/helpdata/en/fc/eb387a358411d1829f0000e829fbfe/content.htm
THANKS
MRUTYUN

Dynamic select with field symbols

Hi guys,
I have 2 tables.
First table is the popup fields using fm popup_get_values:
tab1-tabname
tab1-fieldname
tab1-value
Second table is the input fields to be displayed in the popup box:
tab2-transactno
tab2-docno
tab2-customer
tab2-postdate
etc... (it has many fields)
Let's say currently i loop at tab2 and assign each value of the individual fields to a variable each:
loop at tab2
v_transactno = tab2-transactno
v_docno = tab2-docno
etc...
endloop.
My question is how do i assign each variable to the popup fields according to the fieldname so that it can get its corresponding value correctly?
How can this be done dynamically?
Can the loop above be done dynamically as well coz it has alot of fields to cater for?
Please help me solve this problem. Futher similar examples would be much appreciated as well.
Thank you very much!

Hi
see the concept of field sysmbols and do accordingly
Field Symbols
Field symbols are placeholders or symbolic names for other fields. They do not physically reserve space for a field, but point to its contents. A field symbol cam point to any data object. The data object to which a field symbol points is assigned to it after it has been declared in the program.
Whenever you address a field symbol in a program, you are addressing the field that is assigned to the field symbol. After successful assignment, there is no difference in ABAP whether you reference the field symbol or the field itself. You must assign a field to each field symbol before you can address the latter in programs.
Field symbols are similar to dereferenced pointers in C (that is, pointers to which the content operator * is applied). However, the only real equivalent of pointers in ABAP, that is, variables that contain a memory address (reference) and that can be used without the contents operator, are reference variables in ABAP Objects.
All operations programmed with field symbols are applied to the field assigned to it. For example, a MOVE statement between two field symbols moves the contents of the field assigned to the first field symbol to the field assigned to the second field symbol. The field symbols themselves point to the same fields after the MOVE statement as they did before.
You can create field symbols either without or with type specifications. If you do not specify a type, the field symbol inherits all of the technical attributes of the field assigned to it. If you do specify a type, the system checks the compatibility of the field symbol and the field you are assigning to it during the ASSIGN statement.
Field symbols provide greater flexibility when you address data objects:
If you want to process sections of fields, you can specify the offset and length of the field dynamically.
You can assign one field symbol to another, which allows you to address parts of fields.
Assignments to field symbols may extend beyond field boundaries. This allows you to address regular sequences of fields in memory efficiently.
You can also force a field symbol to take different technical attributes from those of the field assigned to it.
The flexibility of field symbols provides elegant solutions to certain problems. On the other hand, it does mean that errors can easily occur. Since fields are not assigned to field symbols until runtime, the effectiveness of syntax and security checks is very limited for operations involving field symbols. This can lead to runtime errors or incorrect data assignments.
While runtime errors indicate an obvious problem, incorrect data assignments are dangerous because they can be very difficult to detect. For this reason, you should only use field symbols if you cannot achieve the same result using other ABAP statements.
For example, you may want to process part of a string where the offset and length depend on the contents of the field. You could use field symbols in this case. However, since the MOVE statement also supports variable offset and length specifications, you should use it instead. The MOVE statement (with your own auxiliary variables if required) is much safer than using field symbols, since it cannot address memory beyond the boundary of a field. However, field symbols may improve performance in some cases.
check the below links u will get the answers for your questions
http://help.sap.com/saphelp_nw04/helpdata/en/fc/eb3860358411d1829f0000e829fbfe/content.htm
http://www.sts.tu-harburg.de/teaching/sap_r3/ABAP4/field_sy.htm
http://searchsap.techtarget.com/tip/1,289483,sid21_gci920484,00.html
Syntax Diagram
FIELD-SYMBOLS
Basic form
FIELD-SYMBOLS <fs>.
Extras:
1. ... TYPE type
2. ... TYPE REF TO cif
3. ... TYPE REF TO DATA
4. ... TYPE LINE OF type
5. ... LIKE s
6. ... LIKE LINE OF s
7. ... TYPE tabkind
8. ... STRUCTURE s DEFAULT wa
The syntax check performed in an ABAP Objects context is stricter than in other ABAP areas. See Cannot Use Untyped Field Symbols ad Cannot Use Field Symbols as Components of Classes.
Effect
This statement declares a symbolic field called <fs>. At runtime, you can assign a concrete field to the field symbol using ASSIGN. All operations performed with the field symbol then directly affect the field assigned to it.
You can only use one of the additions.
Example
Output aircraft type from the table SFLIGHT using a field symbol:
FIELD-SYMBOLS <PT> TYPE ANY.
DATA SFLIGHT_WA TYPE SFLIGHT.
ASSIGN SFLIGHT_WA-PLANETYPE TO <PT>.
WRITE <PT>.
Addition 1
... TYPE type
Addition 2
... TYPE REF TO cif
Addition 3
... TYPE REF TO DATA
Addition 4
... TYPE LINE OF type
Addition 5
... LIKE s
Addition 6
... LIKE LINE OF s
Addition 7
... TYPE tabkind
Effect
You can define the type of the field symbol using additions 2 to 7 (just as you can for FORM parameters (compare Defining the Type of Subroutine Parameters). When you use the ASSIGN statement, the system carries out the same type checks as for USING parameters of FORMs.
This addition is not allowed in an ABAP Objects context. See Cannot Use Obsolete Casting for FIELD SYMBOLS.
In some cases, the syntax rules that apply to Unicode programs are different than those for non-Unicode programs. See Defining Types Using STRUCTURE.
Effect
Assigns any (internal) field string or structure to the field symbol from the ABAP Dictionary (s). All fields of the structure can be addressed by name: <fs>-fieldname. The structured field symbol points initially to the work area wa specified after DEFAULT.
The work area wa must be at least as long as the structure s. If s contains fields of the type I or F, wa should have the structure s or at least begin in that way, since otherwise alignment problems may occur.
Example
Address components of the flight bookings table SBOOK using a field symbol:
DATA SBOOK_WA LIKE SBOOK.
FIELD-SYMBOLS <SB> STRUCTURE SBOOK
DEFAULT SBOOK_WA.
WRITE: <SB>-BOOKID, <SB>-FLDATE.
Regards
Anji

Mapping individual field symbols to a structure

Hi,
I have a requirement where I need to map some individual field symbols to some specific fields in a structure:.
Here is what mt code looks like :
data: <f1>, <f2> , <f3>,
       <f4> type ZCUSTTAB.
data: upd type ZCUSTTAB.
data : fieldname1(30),
      fieldname2(20),
      fieldname3(20),
      fname1(20),
      fname2(20),
      fname3(20).
fname1 = 'TOUR_ID'.
fname2 = 'VISIT_ID'.
fname3 = 'CUSTNR'.
concatenate 'ZCUSTTAB-' fname1 into fieldname1.
concatenate 'ZCUSTTAB-' fname2 into fieldname2.
concatenate 'ZCUSTTAB-' fname3 into fieldname3.
assign fieldname1 to <f1>.
assign fieldname2 to <f2>.
assign fieldname3 to <f3>.
<f1> = '12345'.
<f2> = '1'.
<f2> = '123'.
So, at this point I have my field symbols pointing towards individual fields , i.e.
<f1> holds value for ZCUSTTAB-TOUR_ID.
<f2> holds value for ZCUSTTAB-VISIT_ID.
<f3> holds value for ZCUSTTAB-CUSTNR.
Now, I want to move these individual values to a structure which is of type ZCUSTTAB, using which I can update the table ZCUSTTAB at DB.
Any ideas on how to achieve this ?
Thanks-

Hi
U need to declar that table and that's all:
TABLES ZCUSTTAB.
data: <f1>, <f2> , <f3>,
       <f4> type ZCUSTTAB.
data: upd type ZCUSTTAB.
data : fieldname1(30),
      fieldname2(20),
      fieldname3(20),
      fname1(20),
      fname2(20),
      fname3(20).
fname1 = 'TOUR_ID'.
fname2 = 'VISIT_ID'.
fname3 = 'CUSTNR'.
concatenate 'ZCUSTTAB-' fname1 into fieldname1.
concatenate 'ZCUSTTAB-' fname2 into fieldname2.
concatenate 'ZCUSTTAB-' fname3 into fieldname3.
assign fieldname1 to <f1>.
assign fieldname2 to <f2>.
assign fieldname3 to <f3>.
<f1> = '12345'.
<f2> = '1'.
<f2> = '123'.
UPDATE ZCUSTTAB.
After assigning the field-symbols the structure ZCUSTTAB will be filled automatically.
U can also write:
TABLES ZCUSTTAB.
data: <f1>, <f2> , <f3>,
       <f4> type ZCUSTTAB.
data: upd type ZCUSTTAB.
data : fieldname1(30),
      fieldname2(20),
      fieldname3(20),
      fname1(20),
      fname2(20),
      fname3(20).
fname1 = 'TOUR_ID'.
fname2 = 'VISIT_ID'.
fname3 = 'CUSTNR'.
assign component fname1 of structure ZCUSTTAB to <f1>.
assign component fname2 of structure ZCUSTTAB to <f2>.
assign component fname3 of structure ZCUSTTAB to <f3>.
<f1> = '12345'.
<f2> = '1'.
<f2> = '123'.
UPDATE ZCUSTTAB.
Max

How to populate values of field symbols?

HI,
I need to pass values into a field-symbol (defined as a dynamic Work Area) and append the values later on into another field-symbol (defined as a dynamic Table) by inserting the work area to the table. The insert statement in the screen shot below is syntetically correct but when I uncomment
*      <gw_itab>-tplnr = 'TPLNR'.
*      <gw_itab>-pmsog = 'PMSOG'.
*      <gw_itab>-k_pro = 'K_PRO'.
I get a syntax error. During debugging if I pass the values of the work area, they are properly appended into the table.
Could somebody show me the code on how to atain this programatically?
Thanks for your help
Carl

From the short dump:
"<GT_ITAB> has line type "v" and the length 24, but the work area has line type "g" and the length 8".
The code you included in your first screenshot is not the code that it dumped on... Looking at the shortdump here's what you have.
lv_fieldname = '<GW_ITAB>-TPLNR'.
assign (lv_fieldname) to <gw_itab>.
<gw_itab> = 'TPLNR'.
insert <gw_itab> into table <gt_itab>.
This code doesn't make any sense...
What you're saying is:
<gw_itab> points to <gw_itab>-tplnr. So now it points to just a field of the structure, not the whole structure.... Then you say that field is set to 'TPLNR'. So you set the field of the original structure called TPLNR to be the string "TPLNR"...
If that's really what you're trying to do then try changing it to:
field-symbols: <field> type any.
lv_fieldname = '<GW_ITAB>-TPLNR'.
assign (lv_fieldname) to <field>.
<field> = 'TPLNR'.
insert <gw_itab> into table <gt_itab>.

How to move field symbol internal table to internal table with header line?

Dear all,
hi...hereby i would like to ask how i can move field symbol internal table to a internal table?
as i know field symbol internal table is without header line..
so, may i know how to do this....to move field symbol internal table to internal table which consist of header line and field and record will same as field symbol internal table...in additional, my field symbol internal table is dynamic table mean everytime will have flexible columns..?
Please advise...
Thanks
Regard,
ToToRo.
Edited by: @ToToRo@ on Aug 20, 2009 6:16 AM

Hello,
Try this way:
If both the type of internal tables are same then you can directly assign dynamic internal table to static internal table.
itab = <itab>.
Suppose you have field symbol internal table <itab> which is different in structure from ITAB.
Now, you can create <wa> as follow:
FIELD-SYMBOLS <wa>.
DATA wa TYPE REF TO DATA.
CREATE DATA wa TYPE LINE OF <itab>.
ASSIGN wa->* to <wa>.
This way your work area is read.
Using [ASSIGN COMPONENT|http://help.sap.com/saphelp_nw04/helpdata/EN/fc/eb3923358411d1829f0000e829fbfe/content.htm] syntax you can read required component of <wa>.
Finally you can use that value to load static internal table.
You can also refer to my thread on [Dynamic table|Re: Creating Dynamic table].
Hope this helps!
Thanks,
Augustin.
Edited by: Augustarian on Aug 20, 2009 10:06 AM

Field symbols?

Hi,
Can any one give me clear idea of field symbols and their use in the programing?
i read some help docs but could not get it what exactly it means
Thanks,
Ravi

Hi
Field Symbols
Field symbols are placeholders or symbolic names for other fields. They do not physically reserve space for a field, but point to its contents. A field symbol cam point to any data object. The data object to which a field symbol points is assigned to it after it has been declared in the program.
Whenever you address a field symbol in a program, you are addressing the field that is assigned to the field symbol. After successful assignment, there is no difference in ABAP whether you reference the field symbol or the field itself. You must assign a field to each field symbol before you can address the latter in programs.
Field symbols are similar to dereferenced pointers in C (that is, pointers to which the content operator * is applied). However, the only real equivalent of pointers in ABAP, that is, variables that contain a memory address (reference) and that can be used without the contents operator, are reference variables in ABAP Objects.
All operations programmed with field symbols are applied to the field assigned to it. For example, a MOVE statement between two field symbols moves the contents of the field assigned to the first field symbol to the field assigned to the second field symbol. The field symbols themselves point to the same fields after the MOVE statement as they did before.
You can create field symbols either without or with type specifications. If you do not specify a type, the field symbol inherits all of the technical attributes of the field assigned to it. If you do specify a type, the system checks the compatibility of the field symbol and the field you are assigning to it during the ASSIGN statement.
Field symbols provide greater flexibility when you address data objects:
If you want to process sections of fields, you can specify the offset and length of the field dynamically.
You can assign one field symbol to another, which allows you to address parts of fields.
Assignments to field symbols may extend beyond field boundaries. This allows you to address regular sequences of fields in memory efficiently.
You can also force a field symbol to take different technical attributes from those of the field assigned to it.
The flexibility of field symbols provides elegant solutions to certain problems. On the other hand, it does mean that errors can easily occur. Since fields are not assigned to field symbols until runtime, the effectiveness of syntax and security checks is very limited for operations involving field symbols. This can lead to runtime errors or incorrect data assignments.
While runtime errors indicate an obvious problem, incorrect data assignments are dangerous because they can be very difficult to detect. For this reason, you should only use field symbols if you cannot achieve the same result using other ABAP statements.
For example, you may want to process part of a string where the offset and length depend on the contents of the field. You could use field symbols in this case. However, since the MOVE statement also supports variable offset and length specifications, you should use it instead. The MOVE statement (with your own auxiliary variables if required) is much safer than using field symbols, since it cannot address memory beyond the boundary of a field. However, field symbols may improve performance in some cases.
check the below links u will get the answers for your questions
http://help.sap.com/saphelp_nw04/helpdata/en/fc/eb3860358411d1829f0000e829fbfe/content.htm
http://www.sts.tu-harburg.de/teaching/sap_r3/ABAP4/field_sy.htm
http://searchsap.techtarget.com/tip/1,289483,sid21_gci920484,00.html
Syntax Diagram
FIELD-SYMBOLS
Basic form
FIELD-SYMBOLS <fs>.
Extras:
1. ... TYPE type
2. ... TYPE REF TO cif
3. ... TYPE REF TO DATA
4. ... TYPE LINE OF type
5. ... LIKE s
6. ... LIKE LINE OF s
7. ... TYPE tabkind
8. ... STRUCTURE s DEFAULT wa
The syntax check performed in an ABAP Objects context is stricter than in other ABAP areas. See Cannot Use Untyped Field Symbols ad Cannot Use Field Symbols as Components of Classes.
Effect
This statement declares a symbolic field called <fs>. At runtime, you can assign a concrete field to the field symbol using ASSIGN. All operations performed with the field symbol then directly affect the field assigned to it.
You can only use one of the additions.
Example
Output aircraft type from the table SFLIGHT using a field symbol:
FIELD-SYMBOLS <PT> TYPE ANY.
DATA SFLIGHT_WA TYPE SFLIGHT.
ASSIGN SFLIGHT_WA-PLANETYPE TO <PT>.
WRITE <PT>.
Addition 1
... TYPE type
Addition 2
... TYPE REF TO cif
Addition 3
... TYPE REF TO DATA
Addition 4
... TYPE LINE OF type
Addition 5
... LIKE s
Addition 6
... LIKE LINE OF s
Addition 7
... TYPE tabkind
Effect
You can define the type of the field symbol using additions 2 to 7 (just as you can for FORM parameters (compare Defining the Type of Subroutine Parameters). When you use the ASSIGN statement, the system carries out the same type checks as for USING parameters of FORMs.
This addition is not allowed in an ABAP Objects context. See Cannot Use Obsolete Casting for FIELD SYMBOLS.
In some cases, the syntax rules that apply to Unicode programs are different than those for non-Unicode programs. See Defining Types Using STRUCTURE.
Effect
Assigns any (internal) field string or structure to the field symbol from the ABAP Dictionary (s). All fields of the structure can be addressed by name: <fs>-fieldname. The structured field symbol points initially to the work area wa specified after DEFAULT.
The work area wa must be at least as long as the structure s. If s contains fields of the type I or F, wa should have the structure s or at least begin in that way, since otherwise alignment problems may occur.
Example
Address components of the flight bookings table SBOOK using a field symbol:
DATA SBOOK_WA LIKE SBOOK.
FIELD-SYMBOLS <SB> STRUCTURE SBOOK
DEFAULT SBOOK_WA.
WRITE: <SB>-BOOKID, <SB>-FLDATE.
Regards
Anji

What exactly are Field symbols?

Hi SDN,
What exactly are Field symbols?
I have read they are not pointers then what are they?
Regards,
Rahul

Hi
see this
Field Symbols
Field symbols are placeholders or symbolic names for other fields. They do not physically reserve space for a field, but point to its contents. A field symbol cam point to any data object. The data object to which a field symbol points is assigned to it after it has been declared in the program.
Whenever you address a field symbol in a program, you are addressing the field that is assigned to the field symbol. After successful assignment, there is no difference in ABAP whether you reference the field symbol or the field itself. You must assign a field to each field symbol before you can address the latter in programs.
Field symbols are similar to dereferenced pointers in C (that is, pointers to which the content operator * is applied). However, the only real equivalent of pointers in ABAP, that is, variables that contain a memory address (reference) and that can be used without the contents operator, are reference variables in ABAP Objects.
All operations programmed with field symbols are applied to the field assigned to it. For example, a MOVE statement between two field symbols moves the contents of the field assigned to the first field symbol to the field assigned to the second field symbol. The field symbols themselves point to the same fields after the MOVE statement as they did before.
You can create field symbols either without or with type specifications. If you do not specify a type, the field symbol inherits all of the technical attributes of the field assigned to it. If you do specify a type, the system checks the compatibility of the field symbol and the field you are assigning to it during the ASSIGN statement.
Field symbols provide greater flexibility when you address data objects:
If you want to process sections of fields, you can specify the offset and length of the field dynamically.
You can assign one field symbol to another, which allows you to address parts of fields.
Assignments to field symbols may extend beyond field boundaries. This allows you to address regular sequences of fields in memory efficiently.
You can also force a field symbol to take different technical attributes from those of the field assigned to it.
The flexibility of field symbols provides elegant solutions to certain problems. On the other hand, it does mean that errors can easily occur. Since fields are not assigned to field symbols until runtime, the effectiveness of syntax and security checks is very limited for operations involving field symbols. This can lead to runtime errors or incorrect data assignments.
While runtime errors indicate an obvious problem, incorrect data assignments are dangerous because they can be very difficult to detect. For this reason, you should only use field symbols if you cannot achieve the same result using other ABAP statements.
For example, you may want to process part of a string where the offset and length depend on the contents of the field. You could use field symbols in this case. However, since the MOVE statement also supports variable offset and length specifications, you should use it instead. The MOVE statement (with your own auxiliary variables if required) is much safer than using field symbols, since it cannot address memory beyond the boundary of a field. However, field symbols may improve performance in some cases.
check the below links u will get the answers for your questions
http://help.sap.com/saphelp_nw04/helpdata/en/fc/eb3860358411d1829f0000e829fbfe/content.htm
http://www.sts.tu-harburg.de/teaching/sap_r3/ABAP4/field_sy.htm
http://searchsap.techtarget.com/tip/1,289483,sid21_gci920484,00.html
Syntax Diagram
FIELD-SYMBOLS
Basic form
FIELD-SYMBOLS <fs>.
Extras:
1. ... TYPE type
2. ... TYPE REF TO cif
3. ... TYPE REF TO DATA
4. ... TYPE LINE OF type
5. ... LIKE s
6. ... LIKE LINE OF s
7. ... TYPE tabkind
8. ... STRUCTURE s DEFAULT wa
The syntax check performed in an ABAP Objects context is stricter than in other ABAP areas. See Cannot Use Untyped Field Symbols ad Cannot Use Field Symbols as Components of Classes.
Effect
This statement declares a symbolic field called <fs>. At runtime, you can assign a concrete field to the field symbol using ASSIGN. All operations performed with the field symbol then directly affect the field assigned to it.
You can only use one of the additions.
Example
Output aircraft type from the table SFLIGHT using a field symbol:
FIELD-SYMBOLS <PT> TYPE ANY.
DATA SFLIGHT_WA TYPE SFLIGHT.
ASSIGN SFLIGHT_WA-PLANETYPE TO <PT>.
WRITE <PT>.
Addition 1
... TYPE type
Addition 2
... TYPE REF TO cif
Addition 3
... TYPE REF TO DATA
Addition 4
... TYPE LINE OF type
Addition 5
... LIKE s
Addition 6
... LIKE LINE OF s
Addition 7
... TYPE tabkind
Effect
You can define the type of the field symbol using additions 2 to 7 (just as you can for FORM parameters (compare Defining the Type of Subroutine Parameters). When you use the ASSIGN statement, the system carries out the same type checks as for USING parameters of FORMs.
This addition is not allowed in an ABAP Objects context. See Cannot Use Obsolete Casting for FIELD SYMBOLS.
In some cases, the syntax rules that apply to Unicode programs are different than those for non-Unicode programs. See Defining Types Using STRUCTURE.
Effect
Assigns any (internal) field string or structure to the field symbol from the ABAP Dictionary (s). All fields of the structure can be addressed by name: <fs>-fieldname. The structured field symbol points initially to the work area wa specified after DEFAULT.
The work area wa must be at least as long as the structure s. If s contains fields of the type I or F, wa should have the structure s or at least begin in that way, since otherwise alignment problems may occur.
Example
Address components of the flight bookings table SBOOK using a field symbol:
DATA SBOOK_WA LIKE SBOOK.
FIELD-SYMBOLS <SB> STRUCTURE SBOOK
DEFAULT SBOOK_WA.
WRITE: <SB>-BOOKID, <SB>-FLDATE.
Regards
Anji

Reading a field symbol whose structure is dynamic

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