| Subject | RE: [firebird-support] Pre-testing delete for referential integrity issues |
|---|---|
| Author | Leyne, Sean |
| Post date | 2009-09-01T01:11:45Z |
Myles,
I would try this approach, open a separate thread with a separate db connection, attempt to delete the target row, if successful you know that the delete button can be enabled, if not then the reocrd can't be deleted -- in either case you would always rollback the 'delete' transaction.
Sean
________________________________________
From: firebird-support@yahoogroups.com [firebird-support@yahoogroups.com] On Behalf Of Myles Wakeham [myles@...]
Sent: Monday, August 31, 2009 8:51 PM
To: firebird-support@yahoogroups.com
Subject: [firebird-support] Pre-testing delete for referential integrity issues
I'm wondering if there is a 'best practice' for doing this. I have a
database full of contact records. Of these, many have related tables of
data that I can't delete the contact until those related records are
re-assigned to other parties. Consequently a Cascade delete rule won't
work here.
But rather than giving the user the ability to 'try' to delete the
record and be told that they can't because of a violation of a
referential integrity rule, I'd like to be more pro-active with this and
only give them a delete option of the contact record has no related data
that would stop a delete from occuring.
Is there is a good and fast way to determine if one of these records
could be deleted other than giving the user the ability to try and then
be told they can't? I'm basically trying to simplify their world a bit
by being proactive and telling them up-front that a record can or cannot
be deleted as it stands.
All suggestions, comments, flames, etc. are actually greatly appreciated.
Myles
--
=======================
Myles Wakeham
Director of Engineering
Tech Solutions USA, Inc.
Scottsdale, Arizona USA
http://www.techsolusa.com
Phone +1-480-451-7440
------------------------------------
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Visit http://www.firebirdsql.org and click the Resources item
on the main (top) menu. Try Knowledgebase and FAQ links !
Also search the knowledgebases at http://www.ibphoenix.com
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Yahoo! Groups Links
http://docs.yahoo.com/info/terms/
I would try this approach, open a separate thread with a separate db connection, attempt to delete the target row, if successful you know that the delete button can be enabled, if not then the reocrd can't be deleted -- in either case you would always rollback the 'delete' transaction.
Sean
________________________________________
From: firebird-support@yahoogroups.com [firebird-support@yahoogroups.com] On Behalf Of Myles Wakeham [myles@...]
Sent: Monday, August 31, 2009 8:51 PM
To: firebird-support@yahoogroups.com
Subject: [firebird-support] Pre-testing delete for referential integrity issues
I'm wondering if there is a 'best practice' for doing this. I have a
database full of contact records. Of these, many have related tables of
data that I can't delete the contact until those related records are
re-assigned to other parties. Consequently a Cascade delete rule won't
work here.
But rather than giving the user the ability to 'try' to delete the
record and be told that they can't because of a violation of a
referential integrity rule, I'd like to be more pro-active with this and
only give them a delete option of the contact record has no related data
that would stop a delete from occuring.
Is there is a good and fast way to determine if one of these records
could be deleted other than giving the user the ability to try and then
be told they can't? I'm basically trying to simplify their world a bit
by being proactive and telling them up-front that a record can or cannot
be deleted as it stands.
All suggestions, comments, flames, etc. are actually greatly appreciated.
Myles
--
=======================
Myles Wakeham
Director of Engineering
Tech Solutions USA, Inc.
Scottsdale, Arizona USA
http://www.techsolusa.com
Phone +1-480-451-7440
------------------------------------
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Visit http://www.firebirdsql.org and click the Resources item
on the main (top) menu. Try Knowledgebase and FAQ links !
Also search the knowledgebases at http://www.ibphoenix.com
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Yahoo! Groups Links
http://docs.yahoo.com/info/terms/