ABAP TIP Field Symlbo Tip

ABAP Field Symlbo Tip

The one of lots of field symbol advantage of is efficiency because field symbol doesn’t occupy memory space and only have a reference to other variable.

When there is a need to improve filed symbol performance with BINARY SEARCH, we can sort field symbol.

In this case, the inter table defined with field symbol should declared as a standard type.

SORT <fs1> BY ('CARRID').

REPORT  zfieldsymbol01. DATA : gt_scarr TYPE TABLE OF scarr. FIELD-SYMBOLS : <fs1> TYPE STANDARD TABLE,                 <fs2> TYPE ANY. SELECT * INTO TABLE gt_scarr FROM scarr. ASSIGN gt_scarr TO <fs1>. SORT <fs1> BY ('CARRID'). READ TABLE <fs1> WITH KEY ('CARRID') = 'AA' ASSIGNING <fs2>                  BINARY SEARCH. WRITE <fs2>.

Like this case, when field symbol is defined with TYPE ANY, you can sort the internal table like below program.

SORT <itab> BY (otab).

REPORT  zsort. PARAMETERS p_dbtab TYPE c LENGTH 30. DATA : GV_COLUMN TYPE C LENGTH 30. SELECT-OPTIONS columns FOR GV_COLUMN NO INTERVALS. PARAMETERS : p_ASC RADIOBUTTON GROUP OPT1,              p_DSC RADIOBUTTON GROUP OPT1. PARAMETERS p_where type c LENGTH 255. DATA: otab  TYPE abap_sortorder_tab,       oline TYPE abap_sortorder,       dref  TYPE REF TO data. FIELD-SYMBOLS: <column> LIKE LINE OF columns,                <itab> TYPE STANDARD TABLE. TRY.     CREATE DATA dref TYPE STANDARD TABLE OF (p_dbtab).     ASSIGN dref->* TO <itab>.   CATCH cx_sy_create_data_error.     MESSAGE 'Wrong data type!' TYPE 'I' DISPLAY LIKE 'E'.     LEAVE PROGRAM. ENDTRY. TRY.     SELECT *            FROM (p_dbtab)            INTO TABLE <itab>            where (p_where).   CATCH cx_sy_dynamic_osql_semantics.     MESSAGE 'Wrong database table!' TYPE 'I' DISPLAY LIKE 'E'.     LEAVE PROGRAM. ENDTRY. LOOP AT columns ASSIGNING <column>.   oline-name = <column>-low.   IF P_DSC = 'X'.      oline-descending = P_DSC.   ENDIF.   APPEND oline TO otab. ENDLOOP. TRY.     SORT <itab> BY (otab).   CATCH cx_sy_dyn_table_ill_comp_val.     MESSAGE 'Wrong column name!' TYPE 'I' DISPLAY LIKE 'E'.     LEAVE PROGRAM. ENDTRY.