Appending Summarized Lines 

The following special statement allows you to summate entries in an internal table:

COLLECT wa INTO itab.

itab must have a flat line type, and all of the fields that are not part of the table key must have a numeric type (f, i, p). You specify the line wathat you want to add as a work area that is compatible with the line type of itab.

When the line is inserted, the system checks whether there is already a table entry that matches the key. If there is no corresponding entry already in the table, the COLLECT statement has the same effect as inserting the new line. If an entry with the same key already exists, the COLLECT statement does not append a new line, but adds the contents of the numeric fields in the work area to the contents of the numeric fields in the existing entry.

REPORT demo_int_tables_COLLECT .

DATA: BEGIN OF line,
        col1(3) TYPE c,
        col2(2) TYPE n,
        col3    TYPE i,
      END OF line.

DATA itab LIKE SORTED TABLE OF line
          WITH NON-UNIQUE KEY col1 col2.

line-col1 = 'abc'. line-col2 = '12'. line-col3 = 3.
COLLECT line INTO itab.
WRITE / sy-tabix.

line-col1 = 'def'. line-col2 = '34'. line-col3 = 5.
COLLECT line INTO itab.
WRITE / sy-tabix.

line-col1 = 'abc'. line-col2 = '12'. line-col3 = 7.
COLLECT line INTO itab.
WRITE / sy-tabix.

LOOP AT itab INTO line.
  WRITE: / line-col1, line-col2, line-col3.
ENDLOOP.

The list output is:

         1

         2

         1

abc 12          10

def 34          5

The example fills a sorted table. The first two COLLECT statements work like normal insertion statements. In the third COLLECTstatement, the first line of itab is modified. The following diagram shows the three steps: