Data Corruption?

[tdalber]

I have a database that keeps track of commercial facilities, facility contacts, facility inspections, and phone log entries. Each of these is a different table: tblSite; tblContact; tblInspection; tblPhoneLog.
The Primary Key of tblSite is an alphanumeric concatenation. The Primary Key of the other tables is an autonumber.
It is a linked database, backend sits on a network server, frontend copy is placed on each user's C: drive. Database has been in full use since Oct, 2004.

The issue I have recently discovered is this:
Each Inspection and Phone Log has a Foreign Key linking it to a facility; these are fine. Each also has a Foreign Key linking a Contact to the (Inspection/Phone Log). Sometime last year (approximately May or June), SOMETHING happened that caused the value of the Foreign Key ContactID in each Inspection and Phone Log record dated Oct, 2007 back, to be RANDOMLY CHANGED to a different ContactID.
No records dated Nov, 2007 forward were affected, but the changed Foreign Key ContactIDs included Contacts that were entered as late as May, 2008 (hence my belief that the snafu occurred in that time frame).

I have been working with Access since about '98, and have never seen or heard of this happening before. Does anyone have any experience with this, or have any idea how this could have happened.



Thanks very much,
Terry

[tdalber]

Okay, it looks like Bill Gates strikes again.

I was looking at this wrong. The Foreign Keys in the Inspection and Phone Log tables were not altered, it was the Autonumber Primary Key in the Contact table that was.

This site explains the issue and offers a solution.

After I attempt the solution, I'll check back with final solution.

[tdalber]

Using an old backup of my data, I had to run a compare and update query to fix the references. Very messy and very labor intensive (though I was able to reduce the manual fixes from 6300 to 300).