Showing Optionality in a Relationship Diagram

[Amy E. Baggott]

I am trying to create an ERD for an existing Access database. I've imported
the tables, and I am now trying to create the relationships I want. I can
see how you set cardinality (1-1, 1-many, etc.), but I can't see how you can
set optionality and show it on the diagram (e.g., "Each COMPANY may have one
or more ORDERS" vs. Each ORDER must have one and only one TRACKING RECORD").
In the Database Design course I'm taking, my instructor says that it should
be shown using either a dotted line on the "may" end or a solid line on the
"must" end. So between COMPANY and ORDERS, there would be a line that is
dotted on the COMPANY end, but solid on the ORDER end, while in the second
example, the line would be solid all the way across. How would I do this in
Visio?

 

[Michel LAPLANE \(MVP\)]

Did you try "Database=>Options=>Document=>Relation" ?

Enjoy with Visio

 

[Amy E. Baggott]

I looked there, but didn't see anything for optionality.

--
Amy E. Baggott

"I''m going crazy and I''m taking all of you with me!" -- Linda Grayson

Did you try "Database=>Options=>Document=>Relation" ?

Enjoy with Visio

 

[Michel LAPLANE \(MVP\)]

Well i think optionality is cardinality with a relation of 0 to 1 or 0 to n.
You can choose to have the display of cardinality or Crow's feet that
display dotted line.
Don't forget you have also the possibility to use IDEF1X
notation(Database=>Options=>Document=>General) that can also display the
optionality in the table near the column name
(Database=>Options=>Document=>Table)

Enjoy with visio.

I looked there, but didn't see anything for optionality.