ARTICLE
Standard Keys in Internal Tables
The standard key in
internal tables basically consists of
all the table fields with the character-type type (
C , STRING , D , T , N , X ,
XSTRING ). In particular, components with a
numeric type and table components
in general do not belong to the standard key.
In internal tables with a nested line structure, the standard key
results from linearization of the line structure, that is, all
substructures are resolved recursively until only unstructured table
fields are left to be considered. Of these fields, only those fields
that are neither numeric fields nor tables are included in the key.
The linearization is explained in the following example:
TYPES: BEGIN OF PERSONNEL_DATES,
NAME TYPE STRING,
BIRTHDAY TYPE D,
WEIGHT TYPE F,
END OF PERSONNEL_DATES,
BEGIN OF ADDRESS,
STREET TYPE STRING,
CITY(30) TYPE C,
END OF ADDRESS,
BEGIN OF PERSON_RECORD,
NUMBER(10) TYPE P,
DATES TYPE PERSONNEL_DATES,
ADR TYPE ADDRESS,
END OF PERSON_RECORD.
DATA: ITAB TYPE PERSON_RECORD OCCURS 100.
The standard key for the internal table ITAB is composed of the
fields ITAB-DATES-NAME , ITAB-DATES-BIRTHDAY ,
ITAB-ADR-STREET , and ITAB-ADR-CITY . The fields
ITAB-NUMBER and ITAB-DATES-WEIGHT do not belong to the
standard key.
For tables of non-structured types (that is,tables with an elementary
line type, for example C , I , P , REF TO
etc.), the whole line is used as a standard key.
In contrast, for tables over tables, the standard key is empty.
Documentation extract taken from SAP system, � Copyright SAP AG. All rights reserved