control break statements

[Former Member]

Hi friends,

pls explain , what is the use of control break statements( at first, at last, at new, at end of, on change of ) ? and practical difference applying at new and on change.

Pls send me material or links related to control break statements.

Thanks in advance.

SR K

[Former Member]

Hi

All this AT NEW, AT FIRST, AT END OF and AT LAST are called control break statements of Internal tables and are used to calculate the TOTALS based on sertain key fields in that internal table

FIrst to use these statements the ITAB has to be sorted by the key fields on whcih you need the SUM of the fields.

Some time you will get * when mopving data from this int table to other table using these commands

so you have to use

READ TABLE ITAB INDEX SY-TABIX in AT..ENDAT..if you are using other fields between them

DATA: sflight_tab TYPE SORTED TABLE OF sflight

WITH UNIQUE KEY carrid connid fldate,

sflight_wa LIKE LINE OF sflight_tab.

SELECT *

FROM sflight

INTO TABLE sflight_tab.

LOOP AT sflight_tab INTO sflight_wa.

AT NEW connid.

WRITE: / sflight_wa-carrid,

sflight_wa-connid.

ULINE.

ENDAT.

WRITE: / sflight_wa-fldate,

sflight_wa-seatsocc.

AT END OF connid.

SUM.

ULINE.

WRITE: / 'Sum',

sflight_wa-seatsocc UNDER sflight_wa-seatsocc.

SKIP.

ENDAT.

AT END OF carrid.

SUM.

ULINE.

WRITE: / 'Carrier Sum',

sflight_wa-seatsocc UNDER sflight_wa-seatsocc.

NEW-PAGE.

ENDAT.

AT LAST.

SUM.

WRITE: / 'Overall Sum',

sflight_wa-seatsocc UNDER sflight_wa-seatsocc.

ENDAT.

ENDLOOP.

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Regards

Anji

[Former Member]

Hi SR K,

Control Break Statements are mainly used when you want to track changes of values in any particular column of your internal table, based on which you would proceed with further logic.

Best Example would be to calculate SUM, Sub-Totals of your internal table records....

At New - This event is triggered when it encounters the first record of your internal table

On Change of - This event is triggered only when the value changes for the first time in that column that you have specified.

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Best Regards,

Ram.

[Former Member]

Hello SR K,

Just go through the following documentation.

AT - Control breaks with extracts

Variants:

1. AT NEW f.

2. AT END OF f.

3. AT FIRST.

4. AT LAST.

5. AT fg.

Effect In a LOOP which processes a dataset created with EXTRACT, you

can use special control structures for control break

processing. All these structures begin with AT and end with

ENDAT. The sequence of statements which lies between is

executed whenever a control break occurs.

You can use these key words for control break processing with

extract datasets only if the active LOOP statement is

processing an extract dataset.

The control level structure with extract datasets is dynamic.

It corresponds exactly to the sort key of the extract dataset,

i.e. to the order of fields in the field group HEADER by which

the extract dataset was sorted.

At the end of a control group (AT END OF, AT LAST), there are

two types of control level information between AT and ENDAT:

- If the sort key of the extract dataset contains a

non-numeric field h (particularly in the field group

HEADER), the field CNT(h) contains the number of control

breaks in the (subordinate) control level h.

- For extracted number fields g (see also ABAP Number Types),

the fields SUM(g) contain the relevant control totals.

Notes 1. The fields CNT(h) and SUM(g) can only be addressed after

they have been sorted. Otherwise, a runtime error may

occur.

2. The fields CNT(h) and SUM(g) are filled with the relevant

values for a control level at the end of each control group

(AT END OF, AT LAST), not at the beginning (AT FIRST, AT

NEW).

3. When calculating totals with SUM(g), the system

automatically chooses the maximum field sizes so that an

overflow occurs only if the absolute value area limits are

exceeded.

4. You can also use special control break control structures

with LOOPs on internal tables.

Variant 1 AT NEW f.

Variant 2 AT END OF f.

Effect f is a field from the field group HEADER. The enclosed

sequence of statements is executed if

- the field f occurs in the sort key of the extract dataset

(and thus also in the field group HEADER) and

- the field f or a superior sort criterion has a different

value in the current LOOP line than in the preceding (AT

NEW) or subsequent (AT END OF) record of the extract

dataset.

If f is not an assigned field symbol, the control break

criterion is ignored, and the subsequent sequence of

statements is not executed. If a field symbol is assigned, but

does not point to the HEADER field group, the system triggers

a runtime error.

Example

DATA: NAME(30),

SALES TYPE I.

FIELD-GROUPS: HEADER, INFOS.

INSERT: NAME INTO HEADER,

SALES INTO INFOS.

...

LOOP.

AT NEW NAME.

NEW-PAGE.

ENDAT.

...

AT END OF NAME.

WRITE: / NAME, SUM(SALES).

ENDAT.

ENDLOOP.

Notes 1. If the extract dataset is not sorted before processing with

LOOP, no control level structure is defined and the

statements following AT NEW or AT END OF are not executed.

2. Fields which stand at hex zero are ignored by the control

break check with AT NEW or AT END OF. This corresponds to

the behavior of the SORT statement, which always places

unoccupied fields (i.e. fields which stand at hex zero)

before all occupied fields when sorting extract datasets,

regardless of whether the sort sequence is in ascending or

descending order.

Variant 3 AT FIRST.

Variant 4 AT LAST.

Effect Executes the relevant series of statements just once - either

on the first loop pass (with AT FIRST) or on the last loop

pass (with AT LAST).

Variant 5 AT fg.

Addition:

... WITH fg1

Effect This statement makes single record processing dependent on the

type of extracted record.

The sequence of statements following AT fg are executed

whenever the current LOOP record is created with EXTRACT fg

(in other words: when the current record is a fg record).

Addition ... WITH fg1

Effect Executes the sequence of statements belonging to AT fg WITH

fg1 only if the record of the field group fg in the dataset is

immediately followed by a record of the field group fg1.

Reward If Helpful

Regards

--

Sasidhar Reddy Matli.

[Former Member]

Hi,

try this example and look at the results.

TABLES: VBAP.

*

DATA: ITAB TYPE TABLE OF VBAP WITH HEADER LINE.

*

SELECT * FROM VBAP INTO TABLE ITAB UP TO 100 ROWS.

*

LOOP AT ITAB.

WRITE: / 'without any', ITAB-VBELN.

AT FIRST.

WRITE: / 'at first', ITAB-VBELN.

ENDAT.

ON CHANGE OF ITAB-VBELN.

WRITE: / 'on change of', ITAB-VBELN.

ENDON.

AT NEW VBELN.

WRITE: / 'at new', ITAB-VBELN.

ENDAT.

AT END OF VBELN.

WRITE: / 'at end of', ITAB-VBELN.

ENDAT.

AT LAST.

WRITE: / 'at last', ITAB-VBELN.

ENDAT.

ENDLOOP.

Regards, Dieter

[Former Member]

Hi,

solved?!?!

Regards, Dieter