SAP ABAP count lines in internal table with where condition

Ex1 REDUCE

Definition REDUCE

... REDUCE type(
      [let_exp]
      INIT {x1 = rhs1}|{ = wrexpr1}|{x1| TYPE dtype1}
           {x2 = rhs2}|{ = wrexpr2}|{x2| TYPE dtype2}
           ...
      FOR for_exp1
      FOR for_exp2
      ...
      NEXT ...
           {x1 = rhs1}|{ = wrexpr1}
           {x2 = rhs2}|{ = wrexpr2}
           ... ) ...

While VALUE and NEW expressions can include FOR expressions, REDUCE must include at least one FOR expression. You can use all kinds of FOR expressions in REDUCE:

• with IN for iterating internal tables
• with UNTIL or WHILE for conditional iterations

Source: https://help.sap.com/doc/abapdocu_751_index_htm/7.51/en-us/abenconstructor_expression_reduce.htm

Before 7.40

DATA: lv_lines TYPE i. 
LOOP AT gt_itab INTO ls_itab where F1 = ‘XYZ’. 
  lv_lines = lv_lines + 1.
ENDLOOP.

After 7.40

DATA(lv_lines) = REDUCE i( INIT x = 0 FOR wa IN gt_itab
                    WHERE( F1 = ‘XYZ’ ) NEXT x = x + 1 ).

Source: https://blogs.sap.com/2015/10/25/abap-740-quick-reference/

Example

SELECT *
 FROM mara
 INTO TABLE @DATA(lt_mara)
 UP TO 10 ROWS.

DATA(lv_count) = REDUCE i( INIT i = 0 FOR wa IN lt_mara WHERE ( aenam EQ 'MARSLAN' ) NEXT i = i + 1 ).

TYPES:
  BEGIN OF ty_material,
    matnr TYPE char40,
    maktx     TYPE char40,
    matkl     TYPE char9,
  END   OF ty_material.
DATA: lt_materials TYPE STANDARD TABLE OF ty_material.
 
 
lt_materials = VALUE #(
  ( matnr = '000000000051000298' maktx = 'Description 1' matkl = 'A' )
  ( matnr = '000000000051003780' maktx = 'Description 2'      matkl = 'A'  )
  ( matnr = '000000000051008389' maktx = 'Description 3' matkl =  'B')
  ( matnr = '000000000051008390' maktx = 'Description 4' matkl = 'C'  )
  ( matnr = '000000000051008394' maktx = 'Description 5' matkl = 'B' )
).
 
 
* Simply get the unique material groups, use WITHOUT MEMBERS
LOOP AT lt_materials INTO DATA(ls_materials)
     GROUP BY  ( matkl = ls_materials-matkl size = GROUP SIZE )
      ASCENDING
      WITHOUT MEMBERS
      REFERENCE INTO DATA(matkl_group).
 
  WRITE: / matkl_group->matkl, matkl_group->size.
ENDLOOP.

Ex2 describe table

append lines of itab to itab1.
delete itab1[] where field1 ne 'XXXX'.
describe table itab1 lines w_lines.
free itab1.

Ex3 LOOP AT

TYPES: BEGIN OF x_count,
matnr TYPE matnr,
count TYPE i,

BEGIN OF x_count.
DATA: i_marc TYPE STANDARD TABLE OF marc,
  i_count TYPE STANDARD TABLE OF x_count,
  wa_count TYPE x_count.
FIELD-SYMBOLS:  TYPE marc.

SELECT * UP TO 1000 ROWS FROM marc INTO TABLE i_marc.

IF sy-subrc = 0.
  SORT i_marc BY matnr.

  LOOP AT i_marc ASSIGNING .
    wa_count-count = wa_count-count + 1.
    AT END OF matnr.
    wa_count-matnr = -matnr.
    APPEND wa_count TO i_count.
    ENDAT.
  ENDLOOP.
ENDIF.

Ex4 Lines (VALUE…)

TYPES: tt_mara TYPE TABLE OF mara WITH EMPTY KEY.
DATA(count) = lines( VALUE tt_mara( FOR line IN lt_mara WHERE ( matnr = 'XXX' ) ( line ) ) ).

Not internal tables for comparison

Ex1n COLLECT

DATA: BEGIN OF seats,
        carrid   TYPE sflight-carrid,
        connid   TYPE sflight-connid,
        seatsocc TYPE sflight-seatsocc,
      END OF seats.

DATA seats_tab LIKE HASHED TABLE OF seats
               WITH UNIQUE KEY carrid connid.

SELECT carrid, connid, seatsocc
       FROM sflight
       INTO @seats.
  COLLECT seats INTO seats_tab.
ENDSELECT.

Ex2n SELECT

select count(*) into l_count
from user_master
where username = l_username and
process_type = processtype and
password = oldpassword group by username.