UPDATE query that fixes orphaned records
Posted
by Jed
on Stack Overflow
See other posts from Stack Overflow
or by Jed
Published on 2010-05-14T16:42:15Z
Indexed on
2010/05/14
16:44 UTC
Read the original article
Hit count: 360
I have an Access database that has two tables that are related by PK/FK. Unfortunately, the database tables have allowed for duplicate/redundant records and has made the database a bit screwy. I am trying to figure out a SQL statement that will fix the problem.
To better explain the problem and goal, I have created example tables to use as reference: You'll notice there are two tables, a Student table and a TestScore table where StudentID is the PK/FK.
The Student table contains duplicate records for students John, Sally, Tommy, and Suzy. In other words the John's with StudentID's 1 and 5 are the same person, Sally 2 and 6 are the same person, and so on.
The TestScore table relates test scores with a student.
Ignoring how/why the Student table allowed duplicates, etc - The goal I'm trying to accomplish is to update the TestScore table so that it replaces the StudentID's that have been disabled with the corresponding enabled StudentID. So, all StudentID's = 1 (John) will be updated to 5; all StudentID's = 2 (Sally) will be updated to 6, and so on. Here's the resultant TestScore table that I'm shooting for (Notice there is no longer any reference to the disabled StudentID's 1-4): Can you think of a query (compatible with MS Access's JET Engine) that can accomplish this goal? Or, maybe, you can offer some tips/perspectives that will point me in the right direction.
Thanks.
© Stack Overflow or respective owner