Operation Manual

Parameter Fields and Prompts
Understanding lists of values
23
Crystal Reports User’s Guide 445
Determining which list-of-values type to use
Different reporting problems require different prompting solutions, depending
on the amount of data in the lists of values. This table provides a rough guide
to which list-of-values design you should use.
Description Unmanaged list of values Managed list of values
Report fields Command objects Business Views
Single-level code
tables. (A table
that has
hundreds of
semi-static
values in a single
level.)
Not well suited.
Because report fields
cannot be filtered, any
filtering of the list that
you require must be
done outside of
Crystal Reports in a
database view.
Well suited.
You can define filtering
within a command
object. (That command
objects return the data
for all levels in the list is
not a problem for
single-level lists.)
Well suited.
You can define filtering
within the source
Business View.
Multi level-
cascading code
tables. (A table
that has
hundreds of
semi-static
values in multiple
levels.)
Well suited.
Provided that the data
filtering is done
outside of Crystal
Reports, report fields
are well suited to
multi-level cascading
code tables because
they retrieve data one
level at a time.
Well suited.
Provided that the total
data volume for all
levels in the list is not
too large. If there is too
much data, you could
encounter performance
issues because
command-object-
based lists of values
retrieve data for all
levels in one trip to the
database.
Well suited.
Business-View-based
lists of values can
support both filtering and
level-by-level data
retrieval.
Fact tables.
(These tables
tend to be very
large, dynamic
tables with
millions of values
in multiple
levels.)
Well suited.
Provided that the
filtering is done
outside of Crystal
Reports in a database
view, and provided
that there is a multi-
level hierarchy to the
data.
Not well suited.
Because command
objects retrieve their
data in one trip to the
database, there could
be performance issues
when you use them
against very large
tables.
Well suited.
Partially scheduled lists
of values excel in this
situation, where the
semi-static part of the
data can be scheduled,
and the most dynamic
part can be retrieved on-
demand.