Difference between Field symbols and field group

Question

Hi experts,
Can you please advice me what is the difference between field symbols and field groups.
Thanks in advance,
Logu.

Answer 1

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 Groups:
A field group is a user-defined grouping of characteristics and basic key figures from the EC-EIS or EC-BP field catalog.
Use
The field catalog contains the fields that are used in the aspects. As the number of fields grows, the field catalog becomes very large and unclear. To simplify maintenance of the aspects, you can group fields in a field group. You can group the fields as you wish, for example, by subject area or responsibility area. A field may be included in several field groups.
When maintaining the data structure of an aspect, you can select the field group that contains the relevant characteristics and basic key figures. This way you limit the number of fields offered.
A field group combines several existing fields together under one name
like
FIELD-GROUPS: fg.
then you can use one insert statement to insert values in fields of field-group.
INSERT f1 f2 ... INTO fg.
Field symbols
If u have experience with 'C', then understand this to be similar to a pointer.
It is used to reference another variable dynamically. So this field symbol will simply point to some other variable. and this pointer can be changed at runtime.
FIELD-SYMBOLS <FS>.
DATA FIELD VALUE 'X'.
ASSIGN FIELD TO <FS>.
WRITE <FS>.
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 Groups:
A field group is a user-defined grouping of characteristics and basic key figures from the EC-EIS or EC-BP field catalog.
Use
The field catalog contains the fields that are used in the aspects. As the number of fields grows, the field catalog becomes very large and unclear. To simplify maintenance of the aspects, you can group fields in a field group. You can group the fields as you wish, for example, by subject area or responsibility area. A field may be included in several field groups.
When maintaining the data structure of an aspect, you can select the field group that contains the relevant characteristics and basic key figures. This way you limit the number of fields offered.
example :
DATA: BEGIN OF SPTAB OCCURS 0,
line(1000), " or type string
END OF SPTAB.
DATA: IDX LIKE SY-INDEX.
field-symbols <FS1>.
split tb_sip AT ';' INTO table sptab.
LOOP AT SPTAB.
IDX = IDX + 1.
ASSIGN COMPONENT IDX OF STRUCTURE tb_detsip TO <FS1>.
If sy-subrc = 0.
<FS1> = SPTAB-line.
Endif.
Endloop.
append tb_detsip.
clear idx.
Field Groups / Extracts
http://help.sap.com/saphelp_46c/helpdata/EN/9f/db9ede35c111d1829f0000e829fbfe/frameset.htm
Field Symbols
http://help.sap.com/saphelp_46c/helpdata/EN/fc/eb387a358411d1829f0000e829fbfe/frameset.htm
Reward points if useful.