ARTICLE
Logical Databases - Selection Views
Selection views are collections of fields from different database
tables. At runtime, additional selections for the fields of these
selection views can be defined using
dynamic selections . These additional selections are passed to the
database and reduce the number of database reads. Before this can
happen, the database tables must be defined for dynamic selections in
the selection include of the logical database and the database program
must be programmed accordingly.
Selection views can be edited by choosing
Extras -> Selection Views
in Logical Database
Builder . They are identified by a three-character key that
describes the origin of the selection view: SAP for predefined
selections views or CUS for customer-defined selection views. In
this way, users can define the selection view that best meets their
requirements for a given logical database.
If a selection view is to be used in a logical database, the only
permitted name is STANDARD and it must be associated with a
logical database. In selection views not associated with a special
logical database, any name can be chosen.
The following rules apply when constructing dynamic selections on
selections screens of logical databases: Only those selection views are
used that have the name STANDARD and that are associated with the
logical database. If a customer-defined selection view (with key CUS
) exists, this view is used; if not, the predefined selection view is
used. If there is no selection view with the name STANDARD
associated with the logical database, dynamic selections are constructed
across all fields of all tables in the logical database.
Selection views have the following elements:
Function groups
In selection views, fields are collected in functional groups. All
fields assigned to a functional group can be found in the view. The
grouping of fields in functional groups facilitates the combination of
fields by content and makes them easier to find later. Functional groups
are defined by assigning a functional group ID and a text. The
functional group ID can consist of any two characters and is important
only when the selection view is being edited.
Tables/nodes
The names of the database tables from which fields can be selected for
the selection view. The fields of each of these tables can be displayed
in the lower part of the screen. The table can be selected by choosing
Select or by doubleclicking the table name or node name.
Fields of the table/node
Here, a field is assigned to a functional group and becomes part of the
selection view. Before a field assigned to a function group can be used
as a dynamic selection in the logical database, the corresponding node
in the database program of the logical database must also be defined
accordingly. A field assigned to a functional group can be flagged for a
preselection. The fields flagged in this way appear as selection
criteria on the selection screen of the dynamic selections. The
preselected fields can be modified by choosing New Field Selection
on this selection screen. A selection list appears of all fields in
the selection view and for which dynamic selections are supported in the
corresponding nodes of the logical database.
Documentation extract taken from SAP system, � Copyright SAP AG. All rights reserved