4-ABAP Internal Tables

7/21/2019 4-ABAP Internal Tables

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What is an ABAP Internal Table and How to Create it?

An Internal table is a temporary table gets created in the memory of application server during program execution

and gets destroyed once the program ends. It is used to hold data temporarily or manipulate the data. It contains

one or more rows with same structure.

An internal table can be defined using the keyword TABLE OF in the DATA statement. Internal table can bedefined by the following ways.

TYPES: BEGIN OF ty_student,

id(5) TYPE n,

name(10) TYPE c,

END OF ty_student.

DATA: gwa_student TYPE ty_student.

"Referring to local data type

DATA: it1 TYPE TABLE OF ty_student.

"Referring to local data object

DATA: it2 LIKE TABLE OF gwa_student.

"Referring to data type in ABAP dictionary

DATA: it3 TYPE TABLE OF mara.

Use the APPEND statement to add data to internal table. First define the work area i.e. define a field string with a

structure similar to row of the internal table. Then place the data in the work area and use the APPEND

statement to add the data from work area to internal table.

*--------------------------------------------------------------*

*Data Types

*--------------------------------------------------------------*


id(5) TYPE n,

name(10) TYPE c,

END OF ty_student.


*--------------------------------------------------------------*

*Data Declaration

*--------------------------------------------------------------*

"Referring to local data type

DATA: it TYPE TABLE OF ty_student.

gwa_student-id = 1.

gwa_student-name = 'JOHN'.



APPEND gwa_student TO it.

gwa_student-id = 2.

gwa_student-name = 'JIM'.


gwa_student-id = 3.

gwa_student-name = 'JACK'.


After the last APPEND statement in the above program, internal table ‘IT’ has the following 3 entries. But the

internal table values are not persistent i.e. the internal table and its values are discarded once the program ends.

ID NAME

1 JOHN

2 JIM

3 JACK

Usually internal tables are used to hold data from database tables temporarily for displaying on the screen or

further processing. To fill the internal table with database values, use SELECT statement to read the records

from the database one by one, place it in the work area and then APPEND the values in the work area to internal

table.

DATA: gwa_employee TYPE zemployee,

gt_employee TYPE TABLE OF zemployee.

SELECT * FROM zemployee INTO gwa_employee.

APPEND gwa_employee TO gt_employee.

ENDSELECT.

After ENDSELECT the internal table GT_EMPLOYEE contains all the records that are present in table

ZEMPLOYEE.

Using INTO TABLE addition to SELECT statement we can also read multiple records directly into the internal

table directly. No work area used in this case. This select statement will not work in loop, so no ENDSELECT is

required.

SELECT * FROM zemployee INTO TABLE gt_employee.



Inserting Lines into ABAP Internal TablesWe can insert one or more lines to ABAP internal tables using the INSERT statement. To insert a single line, first

place the values we want to insert in a work area and use the INSERT statement to insert the values in the work

area to internal table.

Syntax to insert a line to internal table

INSERT <work area> INTO TABLE <internal table>.

OR

INSERT <work area> INTO <internal table> INDEX <index>.

The first INSERT statement without INDEX addition will simply add the record to the end of the internal table. But

if we want to insert the line to specific location i.e. if we want to insert it as second record then we need to specify

2 as the index in the INSERT statement.

*--------------------------------------------------------------*

*Data Types

*--------------------------------------------------------------*


id(5) TYPE n,

name(10) TYPE c,

END OF ty_student.

*--------------------------------------------------------------*

*Data Declaration*--------------------------------------------------------------*



gwa_student-id = 1.


INSERT gwa_student INTO TABLE it.

gwa_student-id = 2.



gwa_student-id = 3.



WRITE:/ 'ID' COLOR 5,7 'Name' COLOR 5.

LOOP AT it INTO gwa_student.

WRITE:/ gwa_student-id, gwa_student-name.

ENDLOOP.

SKIP.



WRITE:/ 'After using Index addition' COLOR 4.

gwa_student-id = 4.

gwa_student-name = 'RAM'.

INSERT gwa_student INTO it INDEX 2.




ENDLOOP.

Output

We can also insert multiple lines to an internal table with a single INSERT statement i.e. we can insert the lines ofone internal table to another internal table.

Syntax to insert multiple lines to internal table

INSERT LINES OF <itab1> [FROM <index 1>] [TO <index 2>] INTO TABLE <itab2>.

OR

INSERT LINES OF <itab1> [FROM <index 1>] [TO <index 2>] INTO

<itab2> INDEX <index>.

*--------------------------------------------------------------*

*Data Types

*--------------------------------------------------------------*


id(5) TYPE n,

name(10) TYPE c,

END OF ty_student.

*--------------------------------------------------------------*

*Data Declaration

*--------------------------------------------------------------*




DATA: it TYPE TABLE OF ty_student,

it2 TYPE TABLE OF ty_student,

it3 TYPE TABLE OF ty_student,

it4 TYPE TABLE OF ty_student.

gwa_student-id = 1.



gwa_student-id = 2.



gwa_student-id = 3.



gwa_student-id = 4.

gwa_student-name = 'ROB'.


WRITE:/ 'Inserting all the lines of IT to IT2' COLOR 4.

INSERT LINES OF it INTO TABLE it2.

WRITE:/ 'Display values of IT2' COLOR 1.


LOOP AT it2 INTO gwa_student.


ENDLOOP.

SKIP.

WRITE:/ 'Inserting only lines 2 & 3 of IT to IT3' COLOR 4.

INSERT LINES OF it FROM 2 TO 3 INTO TABLE it3.

WRITE:/ 'Display values of IT3' COLOR 1.




ENDLOOP.

gwa_student-id = 1.

gwa_student-name = 'RAM'.

INSERT gwa_student INTO TABLE it4.

gwa_student-id = 4.



gwa_student-name = 'RAJ'.

INSERT gwa_student INTO TABLE it4.

SKIP.

WRITE:/ 'Inserting only lines 2 & 3 of IT to IT4 at 2' COLOR 4.

INSERT LINES OF it FROM 2 TO 3 INTO it4 INDEX 2.

WRITE:/ 'Display values of it4' COLOR 1.




ENDLOOP.

The last INSERT statement in the above program inserts the 2nd and 3rd line from IT at index 2 in IT4, so the

new lines inserted becomes the 2nd and 3rd line in IT4.

Output



Changing Lines in ABAP Internal TablesMODIFY is the statement to change single or multiple lines in an internal table. Use the INDEX addition to

change a single line. If we use the INDEX addition and the operation is successful, SY-SUBRC will be set to zero

and the contents of the work area overwrites the contents of the line with the corresponding index.

Instead of changing all the values of a row we can specify the fields we want to change by specifying thefieldnames in the TRANSPORTING addition.

MODIFY <internal table> FROM <work area> [INDEX <index>]

[TRANSPORTING <f1> <f2> ... ].

We can also use the above MODIFY statement without INDEX addition inside LOOP. Inside LOOP if we do not

specify the INDEX, then the current loop line will be modified.

We can use the WHERE clause to change single or multiple lines. All the lines that meet the logical condition will

be processed. If at least one line is changed, the system sets SY-SUBRC to 0, otherwise to 4.

MODIFY <internal table> FROM <work area>

TRANSPORTING <f1> <f2> ... WHERE <condition>.

*--------------------------------------------------------------*

*Data Types

*--------------------------------------------------------------*


id(5) TYPE n,

name(10) TYPE c,

place(10) TYPE c,

age TYPE i,

END OF ty_student.

*--------------------------------------------------------------*

*Data Declaration

*--------------------------------------------------------------*



gwa_student-id = 1.


gwa_student-place = 'London'.

gwa_student-age = 20.


gwa_student-id = 2.


gwa_student-place = 'New York'.





gwa_student-id = 3.


gwa_student-place = 'Bangalore'.



gwa_student-id = 4.





WRITE:/ 'Values in IT before MODIFY' COLOR 4.

WRITE:/ 'ID' COLOR 5,7 'Name' COLOR 5, 18 'Place' COLOR 5,

37 'Age' COLOR 5.


WRITE:/ gwa_student-id, gwa_student-name, gwa_student-place,

gwa_student-age.

ENDLOOP.

SKIP.

WRITE:/ 'Values in IT after MODIFY' COLOR 4.

gwa_student-id = 4.


gwa_student-place = 'Mumbai'.


*Change all the columns of row 4 with work area values

MODIFY it FROM gwa_student INDEX 4.


37 'Age' COLOR 5.

LOOP AT it INTO gwa_student.WRITE:/ gwa_student-id, gwa_student-name, gwa_student-place,

gwa_student-age.

ENDLOOP.

SKIP.

WRITE:/ 'Values in IT after Transporting addition' COLOR 4.

gwa_student-id = 9.

gwa_student-name = 'TOM'.



*Change specific columns of row 4 with work area values by



*using TRANSPORTING addition

MODIFY it FROM gwa_student INDEX 4 TRANSPORTING place.


37 'Age' COLOR 5.



gwa_student-age.

ENDLOOP.

SKIP.

WRITE:/ 'Values in IT after MODIFY using WHERE Clause' COLOR 4.

gwa_student-place = 'Mumbai'.

*Change multiple rows using WHERE clause

MODIFY it FROM gwa_student TRANSPORTING place

WHERE place = 'Bangalore'.


37 'Age' COLOR 5.



gwa_student-age.

ENDLOOP.

Output



Deleting Lines from an ABAP Internal TableDELETE is the statement to delete one or more lines from an ABAP Internal Table. Use the INDEX addition to

delete a single line. If we use the INDEX addition and the operation is successful, SY-SUBRC will be set to zero,

the line with the corresponding index in the internal table will be deleted and the indexes of the subsequent lines

will be reduced by one.

DELETE <internal table> [INDEX <index>].

We can also use the above DELETE statement without INDEX addition inside LOOP. Inside LOOP if we do notspecify the INDEX, then the current loop line will be deleted.

We can use the WHERE clause to delete single or multiple lines. All the lines that meet the logical condition will

be deleted. If at least one line is deleted, the system sets SY-SUBRC to 0, otherwise to 4.

DELETE <internal table> [FROM <n1>] [TO <n2>] [WHERE <condition>].

With WHERE clause we can also specify the lines between certain indices that we want to delete by specifying

indexes in FROM and TO additions.

*--------------------------------------------------------------**Data Types



*--------------------------------------------------------------*


id(5) TYPE n,

name(10) TYPE c,

place(10) TYPE c,

age TYPE i,

END OF ty_student.

*--------------------------------------------------------------*

*Data Declaration

*--------------------------------------------------------------*



gwa_student-id = 1.





gwa_student-id = 2.





gwa_student-id = 3.





gwa_student-id = 4.



gwa_student-age = 22.INSERT gwa_student INTO TABLE it.

WRITE:/ 'Values in IT before DELETE' COLOR 4.


37 'Age' COLOR 5.



gwa_student-age.

ENDLOOP.

SKIP.



WRITE:/ 'Values in IT after DELETE' COLOR 4.

*Delete second line from IT

DELETE it INDEX 2.


37 'Age' COLOR 5.



gwa_student-age.

ENDLOOP.

SKIP.

WRITE:/ 'Values in IT after DELETE using WHERE Clause' COLOR 4.

*Delete entries from IT where place is Bangalore

DELETE it WHERE place = 'Bangalore'.


37 'Age' COLOR 5.



gwa_student-age.

ENDLOOP.

Output



More on ABAP Internal TablesDESCRIBE TABLE is the statement to get the attributes like number of lines, line width of each row etc. of

the internal table. DESCRIBE TABLE statement also fills the system fields SY-TFILL (Current no. of lines

in internal table), SY-TLENG (line width of internal table) etc.

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.

SORT <internal table> [ASCENDING|DESCENDING]

We can also delete the adjacent duplicates from an internal table by using the following statement.

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. If at least one line is deleted, the system

sets SY-SUBRC to 0, otherwise to 4.

*--------------------------------------------------------------*

*Data Types

*--------------------------------------------------------------*


id(5) TYPE n,

name(10) TYPE c,

place(10) TYPE c,

age TYPE i,

END OF ty_student.

*--------------------------------------------------------------*

*Data Declaration

*--------------------------------------------------------------*



DATA: gv_lines TYPE i.

gwa_student-id = 1.





gwa_student-id = 2.







gwa_student-id = 3.





gwa_student-id = 4.





gwa_student-id = 2.





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.


37 'Age' COLOR 5.



gwa_student-age.ENDLOOP.

WRITE:/ 'Values in IT after SORT' COLOR 4.

*SORT by name

SORT it BY name DESCENDING.


37 'Age' COLOR 5.



gwa_student-age.





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.

*--------------------------------------------------------------*

*Data Types

*--------------------------------------------------------------*


id(5) TYPE n,

name(10) TYPE c,place(10) TYPE c,

age TYPE i,

END OF ty_student.

*--------------------------------------------------------------*

*Data Declaration

*--------------------------------------------------------------*



DATA: gv_lines TYPE i.



gwa_student-id = 1.





gwa_student-id = 2.





WRITE:/ 'Values in IT before initializing' COLOR 4.


37 'Age' COLOR 5.



gwa_student-age.

ENDLOOP.

*Initialize IT

CLEAR it.

SKIP.

WRITE:/ 'Values in IT before initializing' COLOR 4.


37 'Age' COLOR 5.



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.

Output



Control Break Processing in ABAP InternalTablesControl break processing is used to execute a piece of code whenever a specific condition in the data is detected

during the processing of internal table loop.

The following control break statements are available with in LOOP and ENDLOOP.

AT FIRST / ENDAT

AT LAST / ENDAT

AT NEW / ENDAT

AT END OF / ENDAT

SUM

ON CHANGE OF / ENDON

The code between AT NEW and ENDAT is executed only during the first loop pass. So it is used to write the

headers or some other initialization processing.

The code between AT LAST and ENDAT is executed only during the last loop pass. So it is used to write the

totals or some report footers.

*————————————————————–* *Data Declaration *————————————————————

–*

DATA: gwa_spfli TYPE spfli.

DATA: gt_spfli TYPE TABLE OF spfli.

*UP TO 5 ROWS addition selects only 5 rows from table SPFLI

SELECT * UP TO 5 ROWS FROM spfli INTO TABLE gt_spfli.

LOOP AT gt_spfli INTO gwa_spfli.

AT FIRST.



WRITE:/ 'Start of Loop'.

WRITE:/ 'Flight Details'.

WRITE:/ 'Airline Code' COLOR 5,14 'Connection No.' COLOR 5,

29 'Departure City' COLOR 5, 44 'Arival City' COLOR 5.

ULINE.

ENDAT.

WRITE:/ gwa_spfli-carrid,14 gwa_spfli-connid,

29 gwa_spfli-cityfrom,44 gwa_spfli-cityto.

AT LAST.

ULINE.

WRITE:/ 'End of Loop'.

ENDAT.

ENDLOOP.

Output

Between AT FIRST and ENDAT the work area will not contain any data. The default key fields are filled with

asterisks(*) and the numeric fields are filled with zeros. The ENDAT restores the contents to the values they had

prior to entering the AT FIRST. Changes to the work area within AT FIRST and ENDAT are lost. The same

applies for AT LAST and ENDAT.


–*





*UP TO 5 ROWS addition selects only 5 rows from table SPFLI



AT FIRST.



29 'Departure City' COLOR 5, 44 'Arival City' COLOR 5,

58 'Distance' COLOR 5.

WRITE:/ gwa_spfli-carrid,14 gwa_spfli-connid, 29 gwa_spfli-cityfrom,44 gwa_spfli-cityto, 58 gwa_spfli-distance.

ULINE.

ENDAT.

WRITE:/ gwa_spfli-carrid,14 gwa_spfli-connid,

29 gwa_spfli-cityfrom,44 gwa_spfli-cityto,

58 gwa_spfli-distance.

AT LAST.

ULINE.

WRITE:/ gwa_spfli-carrid,14 gwa_spfli-connid, 29 gwa_spfli-cityfrom,44 gwa_spfli-cityto, 58 gwa_spfli-distance.


ENDAT.

ENDLOOP.

Output



AT NEW and ENDAT is used to detect a change in the value of the field between the loop passes. The field that

is specified in AT NEW is called control level. The code between AT NEW and ENDAT will be executed during

the first loop pass and every time the value of the control level changes or any other field left to the control level

changes. Between AT NEW and ENDAT all the fields in the work area that are right to the control level are filled

with zeros and asterisks.

Similarly The code between AT END OF and ENDAT will be executed during the last loop pass and every time

the value of the control level changes or any other field left to the control level changes.


–*





AT FIRST.





ULINE.

ENDAT.

AT NEW carrid. WRITE:/ gwa_spfli-carrid, ‘ : New Airline’. ULINE. ENDAT.



WRITE:/14 gwa_spfli-connid,

29 gwa_spfli-cityfrom,44 gwa_spfli-cityto,

58 gwa_spfli-distance.

AT END OF carrid. ULINE. WRITE:/ ‘End of Airline : ‘, gwa_spfli-carrid. ULINE. ENDAT.

AT LAST.


ENDAT.

ENDLOOP.

Output

In AT FIRST and AT LAST event blocks the numeric values in the work area contains zeros. SUM

statement calculates the totals of numeric fields and places the totals in the corresponding fields of work area.

In AT NEW and AT END OF event blocks SUM statement finds all the rows within the control level and calculates

the totals of numeric fields that are right to the control level and places the totals in the corresponding fields of

work area.


–*







AT FIRST.





ULINE.

ENDAT.

AT NEW carrid.

WRITE:/ gwa_spfli-carrid, ' : New Airline'.

ULINE.

ENDAT.

WRITE:/14 gwa_spfli-connid,29 gwa_spfli-cityfrom,

44 gwa_spfli-cityto,58 gwa_spfli-distance.

AT END OF carrid.

ULINE.

SUM.

WRITE:/ gwa_spfli-carrid,58 gwa_spfli-distance.

ULINE.

ENDAT.

AT LAST.

SUM.

WRITE:/ 'Total',58 gwa_spfli-distance.




ENDAT.

ENDLOOP.

Output

ON CHANGE OF behaves similar to AT NEW. The syntax is as follows.

ON CHANGE OF <control level1> [or <control level2> . .].

[ELSE.]

ENDON.


–*







AT FIRST.





ULINE.

ENDAT.

ON CHANGE OF gwa_spfli-carrid. WRITE:/ gwa_spfli-carrid, ‘ : New Airline’. ULINE. ENDON.

WRITE:/14 gwa_spfli-connid,29 gwa_spfli-cityfrom,

44 gwa_spfli-cityto,58 gwa_spfli-distance.

ENDLOOP.

Output

Below table summarizes the differences between AT NEW and ON CHANGE OF statements.

AT NEW ON CHANGE OF

It can be used only in AT LOOP

statement.

It can be used in any loop like

SELECT, DO etc..

Only one control field can be Multiple control fields separated



used. by OR can be used.

AT NEW is triggered when a field

left to control level changes.

ON CHANGE OF is not triggered

when a field left to control level

changes.

Values in the fields to the right of

control level contains asterisks

and zeros.

Values in the fields to the right of

control level contains original

values.

ELSE addition cannot be used. ELSE addition can be used.

Changes to work area with AT

NEW will be lost.

Changes to work area with ON

CHANGE OF will not be lost.

Documents

4-ABAP Internal Tables