Oracle FAQ Your Portal to the Oracle Knowledge Grid
HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US
 

Home -> Community -> Usenet -> comp.databases.theory -> Sorting DatabaseTables by FK Constraints

Sorting DatabaseTables by FK Constraints

From: Steven Garcia <stevengarcia_at_yahoo.com>
Date: 23 Dec 2003 08:23:30 -0800
Message-ID: <7f430eb1.0312230823.35bbace4@posting.google.com>


I want to sort a collection of database table definitions (in Java) by FK dependencies. By sorting I mean that Table A is "less than" Table B because Table B has a foreign key constraint that depends on Table A.

If you have a simple schema where there are three tables Table A, Table B, and Table C, and

Table A has a FK constraint on Table B
Table B has a FK constraint on Table C

there should only be (theoreticaly) one correct path to insert records into this schema. You must insert records into Table C, then Table B, then Table A, not in any other order!

I want to make sure that this statement is generally correct.

I've written my own algorithm (I made my Table object in Java implement Comparable for those Java savvy folks) but my sorted Lists are not always correct. I've determined that given a List of Table objects there are many correct "sorted" results and I end up with localized sorted sections but my global sorted list is sometimes incorrect (and sometimes it's correct.)

Has anyone ever attempted to do this? Any advice?

Thanks, Steve Received on Tue Dec 23 2003 - 10:23:30 CST

Original text of this message

HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US