internal tables

[Former Member]

in a loop of an internal table, what is the use of at first &

at last statements?

[Former Member]

Variant 3

AT FIRST.

Variant 4

AT LAST.

Effect

Executes the appropriate sequence of statements once during the first (AT FIRST) or last (AT LAST) loop pass.

Example

TYPES: BEGIN OF COMPANIES_TYPE,

NAME(30),

PRODUCT(20),

SALES TYPE I,

END OF COMPANIES_TYPE.

DATA: COMPANIES TYPE STANDARD TABLE OF COMPANIES_TYPE WITH

NON-UNIQUE DEFAULT KEY INITIAL SIZE 20,

WA_COMPANIES TYPE COMPANIES_TYPE.

...

LOOP AT COMPANIES INTO WA_COMPANIES.

AT FIRST.

SUM.

WRITE: 'Sum of all SALES:',

55 WA_COMPANIES-SALES.

ENDAT.

WRITE: / WA_COMPANIES-NAME, WA_COMPANIES-PRODUCT,

55 WA_COMPANIES-SALES.

ENDLOOP.

Non-Catchable Exceptions

Cause: Invalid sub-field access when dynamically specifying the control break criterion.

Runtime Error: AT_BAD_PARTIAL_FIELD_ACCESS

Cause: When dynamically specifying the control break criterion using a field symbol, the field symbol does not point to the LOOP output area.

Runtime Error: AT_ITAB_FIELD_INVALID

Cause: When dynamically specifying the control break criterion using (name, the field name does not contain a valid subfield name.

Runtime Error: ITAB_ILLEGAL_COMPONENT

Cause: Overflow when totalling with SUM.

Runtime Error: SUM_OVERFLOW

Mvg.

Dirk.

[Former Member]

At first will trigger only first record of internal table

at last will trigger only last record of internal table

See the example program :

&----

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*& Report ZTEST_IEVENTS

*&

&----

---

*&

*&

&----

---

REPORT ZTEST_IEVENTS no standard page heading

line-count 40(2).

tables : vbap.

data : begin of i_vbap occurs 0,

vbeln like vbap-vbeln,

posnr like vbap-posnr,

matnr like vbap-matnr,

kwmeng like vbap-kwmeng,

netpr like vbap-netpr,

end of i_vbap.

data wa_vbap like line of i_vbap.

data v_flag type c.

select-options s_vbeln for vbap-vbeln obligatory.

start-of-selection.

select vbeln

posnr

matnr

kwmeng

netpr from vbap

into table i_vbap

where vbeln in s_vbeln.

sort i_vbap by vbeln posnr.

end-of-selection.

loop at i_vbap.

move i_vbap to wa_vbap.

at first.

write:/2 'Order #',15 'Item #',28 'Material #',50 'Qty', 70 'Net value'.

skip 1.

endat.

at new vbeln.

write:/2 wa_vbap-vbeln,15 wa_vbap-posnr,28 wa_vbap-matnr,

47 wa_vbap-kwmeng,65 wa_vbap-netpr.

v_flag = 'X'.

endat.

if v_flag ne 'X'.

write:/15 wa_vbap-posnr,28 wa_vbap-matnr,

47 wa_vbap-kwmeng,65 wa_vbap-netpr.

endif.

at end of vbeln.

sum.

skip 1.

write:/5 'Sub totals', 47 i_vbap-kwmeng,65 i_vbap-netpr.

skip 1.

endat.

at last .

skip 1.

sum.

write:/5 'Grand Totals',47 i_vbap-kwmeng,65 i_vbap-netpr.

skip 1.

write:/ 'end of page', 'Footer'.

endat.

clear v_flag.

endloop.

[Former Member]

Hi,

When we sort the internal table, depending upon the values of fields, blocks will get created.

A block represents the area of the internal table where the value of a corresponding field remains same.

The processing which we do at the beginning and end of each such blocks is known as control level processing ,

done using at first...endat,

at new...endat,

at end of...endat.

at last...endat,

The whole internal table when sorted can be considered a block, so as we enter the internal table for the first time we do a control level processing using at first..endat, and as we process the last record of the internal table we do a control level processing using at last...endat.

Regards,

Madhusudhan

[Former Member]

Hi

To all gurus helping me out. As iam new to this field.

Thanks&Regards

Suri