Solved

assigning unique primary keys which are two foreign keys in an association table

Posted on 2009-04-11
3
294 Views
Last Modified: 2012-05-06
I have an association table with two foreign keys (e.g. stakeholderID, contactID)  that I would like to express in an er diagram.  The tools I have for drawing the er diagram are ms visio 2007 -- and sql server's diagramming feature through management studio.

also, is there any way to express an alternate key?
0
Comment
Question by:ditallop
  • 2
3 Comments
 
LVL 57

Accepted Solution

by:
Raja Jegan R earned 500 total points
ID: 24123362
So stakeholderID, contactID forms the primary key of that table and in your ER diagram show both of them as primary keys.
What do you mean by Alternate Key
0
 

Author Comment

by:ditallop
ID: 24123415
cool. ultimately i did just that--with the 2 foreign keys in the _assoc table.  alternate keys may be more of an ERwin/Oracle partnership. In general an alternate key (read: AK1, AK2, etc.) is a candidate that could be used to retrieve (generally) unique data but isn't the primary key.  I hate to use the ol' warn employee table as an example ... but its helpful in the case -- so, an emplID or socSecNum might be primary keys, but something like a badgeNum would be an alternate key.
 
0
 

Author Closing Comment

by:ditallop
ID: 31569221
thanks so much for answering...
0

Featured Post

VMware Disaster Recovery and Data Protection

In this expert guide, you’ll learn about the components of a Modern Data Center. You will use cases for the value-added capabilities of Veeam®, including combining backup and replication for VMware disaster recovery and using replication for data center migration.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

In this article I will describe the Backup & Restore method as one possible migration process and I will add the extra tasks needed for an upgrade when and where is applied so it will cover all.
Load balancing is the method of dividing the total amount of work performed by one computer between two or more computers. Its aim is to get more work done in the same amount of time, ensuring that all the users get served faster.
Via a live example, show how to set up a backup for SQL Server using a Maintenance Plan and how to schedule the job into SQL Server Agent.
Viewers will learn how to use the SELECT statement in SQL and will be exposed to the many uses the SELECT statement has.

827 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question