SAP NEWS-46-INTERNAL-TABLES documentation, setup help and example usage

Internal Tables in Release 4.6A

In Release 4.6A, the following new features have been introduced in internal tables:

1 New key specification for unstructured internal tables
2 References as table key
3 Strings as table key
4 Key definition for tables in the ABAP Dictionary
5 Key for unstructured tables
6 Changes to the internal structure
7 Sort without specifying the sort key
8 Access to write-protected tables
9 Index areas in table extensions
10 IS REQUESTED with TABLES parameters
11 Tables as attributes of object types
12 References as line type
13 Multiple identical key specifications


ABAP_MODIFICATION_1 New Key Specification for Unstructured Internal Tables

If the line type of an internal table has no structure, you can use the pseudo component table_line
to specify or address the entire table line as the key. The previous specification, the form TABLE LINE is now obsolete. If a
structure contains a component called
table_line , this leads to a warning in the syntax check.


ABAP_MODIFICATION_2 References as Table Key

References are now allowed in the key of an internal table.


ABAP_MODIFICATION_3 Strings as Table Key

Strings are now allowed in the key of an internal table. This applies to all table types.


ABAP_MODIFICATION_4 Key Definition for tables in the ABAP Dictionary

If you define an internal table in the ABAP Dictionary, it is now possible to specify the table key explicitly.


ABAP_MODIFICATION_5 Default Key of Unstructured Tables

The default key of an internal table without a line structure always consists of the whole line. The exception is a table of a table, which has an empty key.


ABAP_MODIFICATION_6 Change to the Internal Structure

Previously, internal tables have been represented at runtime using a structure 256 bytes long. This has now been replaced by a reference that is only 8 bytes long. This means that structures containing tables as components or tables that contain other tables can now be stored far more efficiently, since an empty table now only requires 8 bytes of memory instead of 256. This is particularly noticeable with structures with only a few entries. Furthermore, the header of a filled table now only requires approximately half of the 256 bytes previously required (the actual figure depends on the platform).

Remember to adjust any structures in the ABAP Dictionary with a field of length 256 bytes intended to accommodate a table header .


ABAP_MODIFICATION_7 Sorting Without Specifying the Sort Key

Sorting an internal table with type
STANDARD or HASHED using the SORT sort statement now returns a correct result, even if you do not specify the sort key in the BY addition.


ABAP_MODIFICATION_8 Accessing Write-Protected Tables

In the DELETE ,
INSERT , and MODIFY statements
,the system returns a syntax error if you specify a write-protected table. This error used to result in a runtime error.


ABAP_MODIFICATION_9 Index Areas with Table Extensions

The statements INSERT LINES OF itab ...
and APPEND LINES OF itab ... return syntax errors if the source table has the type HASHED or ANY andyou use the FROM and TO additions to specify an index range. This error used to result in a runtime error.


ABAP_MODIFICATION_10 IS REQUESTED with TABLES Parameters

When you use the relational operator IS REQUESTED in connection with TABLES parameters in update function modules, the syntax check issues a warning . These parameters are always supplied.


ABAP_MODIFICATION_11 Tables as Attributes of Objects

The LOOP , READ
, SORT ,
DELETE , and MODIFY statements now support access to the attributes of objects as the key of an internal table.

If the line type of an internal table contains object reference variables from ABAP Objects as the component comp , you can use the attributes attr of the object to which the reference is pointing as key values when reading, sorting, and changing the table. This is possible in the following statements:

LOOP AT itab ... WHERE comp- attr ...
READ TABLE itab ... WITH [TABLE] KEY comp- attr = ...
SORT itab BY comp- attr ...
DELETE itab WHERE comp- attr ...
MODIFY itab ... TRANSPORTING ... WHERE comp- attr ...


ABAP_MODIFICATION_12 References as Line Type

In the declarative statements DATA , STATICS , and TYPES
, you may use object and data references as the line type of an internal table.


ABAP_MODIFICATION_13 Multiple Identical Key Specifications

Identical key specifications that occur more than once in the READ statement lead to a warning .

Documentation extract taken from SAP system, � Copyright SAP AG. All rights reserved