INF: Cascade-to-Null relations are supported in JET 4

  • Thread starter Thread starter Allen Browne
  • Start date Start date
A

Allen Browne

In Access 2000 and later, you can create a relation between tables where
related records can be automatically set to Null rather than deleted when
the primary record is deleted.

I have not seen anyone using or discussing this feature, so there is a new
article explaining the concept here:
Cascade to Null Relations
at:
http://allenbrowne.com/ser-64.html
 
In Access 2000 and later, you can create a relation between tables where
related records can be automatically set to Null rather than deleted when
the primary record is deleted.

I have not seen anyone using or discussing this feature, so there is a new
article explaining the concept here:
Cascade to Null Relations
at:
http://allenbrowne.com/ser-64.html
Click to expand...

Allen, can this be done in a similar way in SQL-server? Will upsizing handle it?
 
If you permit changes to the parent key field, perhaps you need:
dbRelationCascadeNull + dbRelationUpdateCascade
to enable the equivalent of:
On Update Cascade, On Delete Set Null


- Steve
 
Thank you Sky.

That is correct if you want cascading updates as well as cascading deletes.
 
polite person said:
Allen, can this be done in a similar way in SQL-server? Will upsizing
handle it?
Click to expand...

The feature, as far as I've understood, was introduced in SQL Server
2005. So it should be available there. DDL through ADO seems to work,
I haven't tested other approaches.
 
Pieter said:
because we're all sensible enough to program cascading deletes <g>
Click to expand...

AFAIK for Access/Jet using ON DELETE CASCADE is the only way of doing
so as a single atomic action.

As someone said, 'Trust the engine, Luke.'

Jamie.

--
 
that's true

Pieter

Jamie Collins said:
AFAIK for Access/Jet using ON DELETE CASCADE is the only way of doing
so as a single atomic action.

As someone said, 'Trust the engine, Luke.'

Jamie.
Click to expand...



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