| SAS/ACCESS Interface to CA-DATACOM/DB: Reference |
Changes to the CA-DATADICTIONARY database
can affect descriptor files. You must fix the descriptors manually if changes
to the CA-DATADICTIONARY database invalidate
the access or view descriptors. Use the ACCESS procedure to update the access
descriptor. Also, update each view descriptor with the ACCESS procedure.
You will receive a message if the view descriptor differs from the access
descriptor. Change the view descriptor as required.
The interface view engine validates a view descriptor when it opens
it. If there is a problem, a message is sent to the LOG window and processing
stops. Therefore, you must change the descriptor files manually when changes
to CA-DATADICTIONARY invalidate them.
- When you change the
CA-DATADICTIONARY database,
you must recreate the access descriptor(s) with PROC ACCESS, using the same
name(s).
- Then you must update each view descriptor with PROC ACCESS. You
will get a message if the view descriptor differs from its access descriptor.
Change the view descriptor as needed.
- The SAS/ACCESS interface view engine does a rudimentary validation
of a view descriptor when it opens it. For example, it checks the data type
information. If it finds a problem, it writes a message to the log and stops.
Before changing
CA-DATADICTIONARY,
consider the guidelines discussed in the next three sections.
|
| Changes That Do Not Affect Existing View Descriptors |
The following changes to the
CA-DATADICTIONARY database
have no effect on existing view descriptors:
- creating or deleting keys, unless you specified a deleted key
as the Default Key.
- adding new fields to a RECORD entity-occurrence.
- deleting fields not referenced in any view
descriptor. (Note
that if an access descriptor includes the deleted item, users could eventually
create a view descriptor using that item, which would be a problem.)
- changing element definitions, as long as a set of one or more
elements still exists that can satisfy view descriptors. The interface view
engine does not require one element per view descriptor; it looks for the
best set of elements for each view descriptor.
- increasing the number of times a field repeats.
|
| Changes That Might Affect Existing View Descriptors |
The following changes to the CA-DATACOM/DB
database
might have an effect on existing view descriptors: changing a field name
or decreasing the number of times a field repeats.
|
| Changes That Cause Existing View Descriptors to Fail |
The following changes to the CA-DATACOM/DB
database
cause existing view descriptors to fail:
- inserting or deleting another level in repeating fields.
- changing the
attributes of a field. Specifically,
- You can change the pictures for character fields, but you cannot
change them to a numeric type field.
- You cannot change a numeric data type to a character data
type.
- deleting fields that are referenced in a view
descriptor.
The interface
view engine validates the view against the current CA-DATADICTIONARY CA-DATACOM/DB
database and issues an informative error message if it detects discrepancies.
Copyright 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.
