Original Question:
        I have a CD contain .DGN files and an Access database file.  The
..DGN files consist of parcels, building footprints, etc.  It appears that
the database is linked or should be to the .DGN files (i.e. the database
contains info on parcel ownership, lot value, etc.).  I am using AV3.2 on
Windows 98 and
have Access 97.  Is there a way to link these .DGN files to the database in
AV.
I have never used database connections before so speak in Lehman's terms if
you have an idea of what I am after.  Thanks for your help.

SUMS:
        (Bob Davis) First thing to realize is that you cannot open your
Access database from the CD, as Access will open a 'record locking' file
(.ldb) for the duration of the open session, so you may have to copy the
database to somewhere else.

Once you have the database where you want it, you can then either use SQL
through ODBC or DDE to access the tables.  I believe 3.2 has an Access
extension, but I don't have 3.2 yet so I can't help with the extension.
However, you can still use SQL if the tables are one-to-one and you only
need to 'join' your tables to your DGNs.

If you want more database functionality (other than Crystal Reporting) such
as query or display in a custom form, you may prefer DDE.  I will include a
simple(?) script showing you how to call a pre-designed Access form (you can
use the Access wizard for this) using the key from the AV coverage as the
'seed' for the form.

My general rule is to use the best tool for the job, and AV, in my opinion,
is a lousy database management tool.  That is why we use Access extensively
to enhance the functionality of AV for database operations.

        (Joe Medeiros) I have linked dgns to access databases many times in
ArcView 3.2. The first thing you should do is bring in the dgns using the
CAD reader extension and then convert them to shape files. It may be easier
to bring in each individual level or element, such as buildings, lots, etc.
and converting them.

When you import a dgn into ArcView, if it had a database linkage it will
hold the mslink once in ArcView. the mslink is what you use to connect to
the database.

Once all of the dgns are converted to shape files, check their table
properties and make sure that the mslink column is there, if so, you are on
the right track.

Next, go into the ODBC data sources, under SETTINGS - CONTROL PANEL. You
want to add a system DSN specifying your access database(s).

With a shape file open, under them main project window, go PROJECT - SQL
CONNECT. Select your database and select the table and all the columns. this
will bring in your database.

With the shape file open, open the table of the active theme and the access
table and select the mslink columns on both. your shape file should be the
destination file, and click join. once they are joined it is recommenced
that you save this as a project. because the database is an ODBC, any
updates done to the database in access will automatically update once you
open your project.

        (Paul Ramsey) Big fat maybe. It entirely depends on the quality of
the ArcView IGDS reader and the quality of the IGDS data. IGDS data does
have the ability to do some rudimentary attribute linkages, but most shops
ignore it and
just plop down text labels -- this will not be any good to you in
ArcView. If things are working, you'll see something like an 'MSLINK' id
number in the IGDS data, and hopefully a column of numbers which match
up in the database attribute table. At the point, you can use an ODBC
data source to bring the attributes into ArcView and just do a join.

If you are not in luck, my company does specialize in just this kind of
data integration task (using the FME from Safe Software www.safe.com),
and could deliver a joined up shape file set to you for a pretty low
price.

Thanks for the help!

Aaron Brault
Vandewalle & Associates
120 East Lakeside Street
Madison, WI  53711
608-255-3988
abrault@vandewalle.com