Few more concepts used with ABAP internal Tables:
DESCRIBE TABLE is the
statement to get the attributes like number of lines, line width of each row
etc. of the internal
table.
Syntax:
Syntax:
DESCRIBE TABLE
<internal table> [LINES <lines>].
SORT is the statement
to sort an ABAP internal table. We can specify the direction of the sort using
the additions ASCENDING and DESCENDING. The default is ascending.
Syntax:
Syntax:
SORT <internal
table> [ASCENDING|DESCENDING]
We can also delete the
adjacent duplicates from an internal table by using the following statement.
Syntax:
Syntax:
DELETE ADJACENT
DUPLICATE ENTRIES FROM <internal table>
[COMPARING <f1>
<f2> ... |ALL FIELDS].
COMPARING ALL FIELDS is
the default. If we do not specify the COMPARING addition, then the system
compares all the fields of both the lines. If we specify fields in the
COMPARING clause, then the system compares only the fields specified after
COMPARING of both the lines.
Example:
*--------------------------------------------------------------*
Example:
*--------------------------------------------------------------*
*Data Types
*--------------------------------------------------------------*
TYPES: BEGIN OF
ty_student,
id(5)
TYPE n,
name(10)
TYPE c,
place(10) TYPE c,
age
TYPE i,
END OF ty_student.
*--------------------------------------------------------------*
*Data Declaration
*--------------------------------------------------------------*
DATA: gwa_student TYPE
ty_student.
DATA: it TYPE TABLE OF ty_student.
DATA: gv_lines TYPE i.
gwa_student-id = 1.
gwa_student-name = 'JOHN'.
gwa_student-place = 'London'.
gwa_student-age = 20.
APPEND gwa_student TO
it.
gwa_student-id = 2.
gwa_student-name = 'JIM'.
gwa_student-place = 'New York'.
gwa_student-age = 21.
APPEND gwa_student TO
it.
gwa_student-id = 3.
gwa_student-name = 'JACK'.
gwa_student-place = 'Bangalore'.
gwa_student-age = 20.
APPEND gwa_student TO
it.
gwa_student-id = 4.
gwa_student-name = 'ROB'.
gwa_student-place = 'Bangalore'.
gwa_student-age = 22.
APPEND gwa_student TO
it.
gwa_student-id = 2.
gwa_student-name = 'JIM'.
gwa_student-place = 'New York'.
gwa_student-age = 21.
APPEND gwa_student TO
it.
DESCRIBE TABLE it LINES
gv_lines.
WRITE:/ 'No. of lines
in IT : ', gv_lines.
WRITE:/ 'SY-TFILL : ',
sy-tfill.
WRITE:/ 'SY-TLENG : ',
sy-tleng.
WRITE:/ 'Values in IT
before SORT' COLOR 4.
WRITE:/ 'ID' COLOR 5,7
'Name' COLOR 5, 18 'Place' COLOR 5,
37 'Age' COLOR 5.
LOOP AT it INTO
gwa_student.
WRITE:/ gwa_student-id, gwa_student-name,
gwa_student-place,
gwa_student-age.
ENDLOOP.
WRITE:/ 'Values in IT
after SORT' COLOR 4.
*SORT by name
SORT it BY name
DESCENDING.
WRITE:/ 'ID' COLOR 5,7
'Name' COLOR 5, 18 'Place' COLOR 5,
37 'Age' COLOR 5.
LOOP AT it INTO
gwa_student.
WRITE:/ gwa_student-id, gwa_student-name,
gwa_student-place,
gwa_student-age.
ENDLOOP.
WRITE:/ 'Values in IT
after deleting duplicates' COLOR 4.
*Delete duplicates
SORT it.
DELETE ADJACENT
DUPLICATES FROM it.
WRITE:/ 'ID' COLOR 5,7
'Name' COLOR 5, 18 'Place' COLOR 5,
37 'Age' COLOR 5.
LOOP AT it INTO
gwa_student.
WRITE:/ gwa_student-id, gwa_student-name,
gwa_student-place,
gwa_student-age.
ENDLOOP.
WRITE:/ 'Values in IT
after deleting duplicates comparing place' COLOR 4.
*Delete duplicates
comparing only place
SORT it BY place.
DELETE ADJACENT
DUPLICATES FROM it COMPARING place.
WRITE:/ 'ID' COLOR 5,7
'Name' COLOR 5, 18 'Place' COLOR 5,
37 'Age' COLOR 5.
LOOP AT it INTO
gwa_student.
WRITE:/ gwa_student-id, gwa_student-name,
gwa_student-place,
gwa_student-age.
ENDLOOP.
We can exit out of LOOP/ENDLOOP processing using EXIT, CONTINUE and CHECK similar to all other LOOPS.
We can also initialize the internal table using FREE, CLEAR and REFRESH statements. CLEAR and REFRESH just initializes the internal table where as FREE initializes the internal table and releases the memory space.
Example:
*--------------------------------------------------------------*
*Data
Types
*--------------------------------------------------------------*
TYPES:
BEGIN OF ty_student,
id(5)
TYPE n,
name(10)
TYPE c,
place(10) TYPE c,
age TYPE i,
END OF ty_student.
*--------------------------------------------------------------*
*Data
Declaration
*--------------------------------------------------------------*
DATA:
gwa_student TYPE ty_student.
DATA:
it TYPE TABLE OF ty_student.
DATA:
gv_lines TYPE i.
gwa_student-id = 1.
gwa_student-name = 'JOHN'.
gwa_student-place = 'London'.
gwa_student-age = 20.
APPEND
gwa_student TO it.
gwa_student-id = 2.
gwa_student-name = 'JIM'.
gwa_student-place = 'New York'.
gwa_student-age = 21.
APPEND
gwa_student TO it.
WRITE:/
'Values in IT before initializing' COLOR 4.
WRITE:/
'ID' COLOR 5,7 'Name' COLOR 5, 18 'Place' COLOR 5,
37 'Age' COLOR 5.
LOOP AT
it INTO gwa_student.
WRITE:/ gwa_student-id, gwa_student-name,
gwa_student-place,
gwa_student-age.
ENDLOOP.
*Initialize
IT
CLEAR
it.
SKIP.
WRITE:/
'Values in IT before initializing' COLOR 4.
WRITE:/
'ID' COLOR 5,7 'Name' COLOR 5, 18 'Place' COLOR 5,
37 'Age' COLOR 5.
LOOP AT
it INTO gwa_student.
WRITE:/ gwa_student-id, gwa_student-name,
gwa_student-place,
gwa_student-age.
ENDLOOP.
*If no
records are processed inside LOOP, then SY-SUBRC <> 0
IF
sy-subrc <> 0.
WRITE:/ 'No records found.'.
ENDIF.
SKIP.
*We can
also use IS INITIAL to check any records found in IT
IF it IS
INITIAL.
WRITE:/ 'No records found in IT.'.
ENDIF.
