ARTICLE
Logical Databases - Selections
The selections on a standard
selection screen of a logical database are defined using the usual
statements used to define selection screens:
PARAMETERS ,
SELECT-OPTIONS ,
SELECTION-SCREEN .
In logical database, the additions
VALUE-REQUEST and HELP-REQUEST
can also be used to define specific input helps. The selection screen is
defined in a special include program, known as the
selection include . The name of this
selection include is DBldbSEL , where ldb stands for the
name of the logical database. This include program cannot be included
explicitly in the database program using an INCLUDE statement. It
is included in the database program and associated programs
automatically when it is generated.
Every executable ABAP program that uses a logical database can add
program-specific selections to the selections of the logical database.
The standard selection screen first displays the database-specific
selections and then the program-specific selections.
When the selection screen of an executable program is created, only
those database-specific selection criteria and parameters are displayed
whose associated tables also have interface work areas declared using
NODES or TABLES in
the program.
The selection screen of a logical database is also part of the
standard selection screen with the
dynpro number 1000 of an executable program associated with the logical
database. It has a standardized layout, with the selection criteria and
parameters in individual lines and in the order declared. The layout can
be edited using the statement
SELECTION-SCREEN .
The ABAP runtime environment generates the selection screen with the
dynpro number 1000 for every program where no other selection screen
version was specified in the program attributes. To prevent certain
input fields of the selection screen of a logical database from
appearing on the screen, selection screen versions (with dynpro numbers
less than 1000) can be defined in the selection include and then entered
in the program attributes. Here, the input help key provides an overview
of the selection screen versions defined in an associated logical
database. Selection screen versions are defined using the statements
SELECTION-SCREEN BEGIN|END OF
VERSION . Within these statements,
SELECTION-SCREEN EXCLUDE
can be used to name the fields to be suppressed on the selection
screen.
If the attributes of an executable program contain the number of a
selection screen version of this type, this number is included in the
standard selection screen. The excluded input fields are not displayed,
but the associated selections still exist and can be edited internally
in the program or filled when called using the function module
LDB_PROCESS .
Note
When a selection include is created, Logical Database
Builder generates a template based on the existing structure.
Here, SELECT-OPTIONS statements are
predefined automatically for all database tables of the structure (nodes
of type T ) and just commented at first. Selection criteria for
each of the primary key fields of each database table are proposed.
If a search help is specified for the
logical database, an appropriate PARAMETERS statement
AS SEARCH PATTERN is predefined. If
specified in the definition of the structure, SELECTION-SCREEN
statements with the additions
DYNAMIC SELECTIONS and
FIELD SELECTION for dynamic
selections and field selections are
generated for nodes of the type T and S .
As well as the element proposals, the selection screen can be modified
as follows:
PARAMETERS can be used to define additional parameters. These can
be used, for example, to check the flow of the program. Here, the
addition FOR TABLE|NODE of the
PARAMETERS statement must be used in the selection include. When the
selection screen is generated, this respects only those parameters for
nodes that are also defined in the executable program using NODES
or TABLES or requested by the function module LDB_PROCESS
.
SELECTION-SCREEN can be used to format the selection screen.
The addition DYNAMIC
SELECTIONS can be used to predefine further nodes for dynamic
selections. At runtime, the user can define for which components of the
node selections can be entered. The dynamic entries must be handled
specially in the database program.
The addition FIELD SELECTION
can be used to predefine further nodes for field selections. Using a
field list in the GET statement, an executable program can
control which fields of the node are to be provided by the logical
database. If the function module LDB_PROCESS is used, the
FIELD_SELECTION parameter must be passed accordingly. The
corresponding user entries must be handled specially in the database
program.
The additions BEGIN OF VERSION
dynnr , EXCLUDE ,
and END OF VERSION can
be used to create various versions of the selection screen with dynpro
numbers less than 1000. This hides input fields of selection criteria or
parameters. In this way, an executable program can work with a suitable
selection screen version.
Example
A selection include contains the lines:
SELECT-OPTIONS slifnr FOR lfa1-lifnr.
PARAMETERS pbukrs LIKE lfb1-bukrs FOR TABLE lfb1.
This associates the selection criterion SLIFNR with the table
LFA1 and the parameter PBUKRS with the table LFB1 .
If only LFA1 but not LFB1 is declared as an interface work
area in an executable program, SLIFNR appears on the selection
screen, but not PBUKRS .
Example
See also Example of a Selection Include
.
Documentation extract taken from SAP system, � Copyright SAP AG. All rights reserved