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Thread: Break referential integrity.

Break referential integrity.

From
Rudi Starcevic
Date:
Hi,

I know that if you have a trigger and function then drop/replace the 
function the trigger needs
to be drop/replaced too so that it can see the new function.

Is it the same for Ref. Integ. on table's too ?

If table B's foreign key references table A and you drop/replace table A
then the reference from table B to table A is broken and needs to be 
recreated ?

Hope I explained that OK.

Thanks
Rudi.

Re: Break referential integrity.

From
Stephan Szabo
Date:
On Wed, 2 Jul 2003, Rudi Starcevic wrote:

> Hi,
>
> I know that if you have a trigger and function then drop/replace the
> function the trigger needs
> to be drop/replaced too so that it can see the new function.
>
> Is it the same for Ref. Integ. on table's too ?
>
> If table B's foreign key references table A and you drop/replace table A
> then the reference from table B to table A is broken and needs to be
> recreated ?

In recent versions, you should not be drop table A without specifying
cascade which will drop the constraint for you (and thus you'll need to
recreate it).  In older versions, I'm not 100% sure what'd happen, but you
probably should drop and recreate it for good measure.

Re: Break referential integrity.

From
Jan Wieck
Date:
Stephan Szabo wrote:
> On Wed, 2 Jul 2003, Rudi Starcevic wrote:
> 
>> Hi,
>>
>> I know that if you have a trigger and function then drop/replace the
>> function the trigger needs
>> to be drop/replaced too so that it can see the new function.
>>
>> Is it the same for Ref. Integ. on table's too ?
>>
>> If table B's foreign key references table A and you drop/replace table A
>> then the reference from table B to table A is broken and needs to be
>> recreated ?
> 
> In recent versions, you should not be drop table A without specifying
> cascade which will drop the constraint for you (and thus you'll need to
> recreate it).  In older versions, I'm not 100% sure what'd happen, but you
> probably should drop and recreate it for good measure.

Older versions spit out a NOTICE and dropped the constraint, so they 
kinda defaulted to CASCADE.


Jan

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