Define FK over DB boundaries

Hi,
is it possible to assign a foreign key from DB1 to a primary key from DB2?
Thanks
Christian
Nope, it's not supported. You'd have to do it with triggers.
HTH. Ryan
"Christian Havel" <ChristianHavel@.discussions.microsoft.com> wrote in
message news:0FB2E334-A203-4BAF-BDA1-71A4462E8841@.microsoft.com...
> Hi,
> is it possible to assign a foreign key from DB1 to a primary key from DB2?
> Thanks
> Christian
|||No, you have to implemt that with triggers.
BTW: Do not cross(-language) post.
HTH, jens Suessmeyer.
|||Hi
You could add a check constraint that calls a function, but this is likely
to be very slow.
John
"Christian Havel" wrote:

> Hi,
> is it possible to assign a foreign key from DB1 to a primary key from DB2?
> Thanks
> Christian
|||> You could add a check constraint that calls a function, but this is likely
> to be very slow.
Careful with this - real DRI works in two directions. This would only work
in one direction and only for inserts and updates.
|||Scott
Both the trigger solution and the check constraint require changes to both
databases if you want to cover everything.
John
"Scott Morris" wrote:

> Careful with this - real DRI works in two directions. This would only work
> in one direction and only for inserts and updates.
>
>
|||> Both the trigger solution and the check constraint require changes to both
> databases if you want to cover everything.
Nothing I wrote disagreed with this. But, as I mentioned, a check
constraint is not checked during deletion. A set of triggers, when properly
designed and written, can enforce the required relationship. As far as I
know, check constraints cannot wholely support the requirement.

Define FK over DB boundaries

Hi,
is it possible to assign a foreign key from DB1 to a primary key from DB2?
Thanks
ChristianNope, it's not supported. You'd have to do it with triggers.
HTH. Ryan
"Christian Havel" <ChristianHavel@.discussions.microsoft.com> wrote in
message news:0FB2E334-A203-4BAF-BDA1-71A4462E8841@.microsoft.com...
> Hi,
> is it possible to assign a foreign key from DB1 to a primary key from DB2?
> Thanks
> Christian|||No, you have to implemt that with triggers.
BTW: Do not cross(-language) post.
HTH, jens Suessmeyer.|||Hi
You could add a check constraint that calls a function, but this is likely
to be very slow.
John
"Christian Havel" wrote:

> Hi,
> is it possible to assign a foreign key from DB1 to a primary key from DB2?
> Thanks
> Christian|||> You could add a check constraint that calls a function, but this is likely
> to be very slow.
Careful with this - real DRI works in two directions. This would only work
in one direction and only for inserts and updates.|||Scott
Both the trigger solution and the check constraint require changes to both
databases if you want to cover everything.
John
"Scott Morris" wrote:

> Careful with this - real DRI works in two directions. This would only wor
k
> in one direction and only for inserts and updates.
>
>|||> Both the trigger solution and the check constraint require changes to both
> databases if you want to cover everything.
Nothing I wrote disagreed with this. But, as I mentioned, a check
constraint is not checked during deletion. A set of triggers, when properly
designed and written, can enforce the required relationship. As far as I
know, check constraints cannot wholely support the requirement.

Define FK over DB boundaries

Hi,
is it possible to assign a foreign key from DB1 to a primary key from DB2?
Thanks
ChristianNope, it's not supported. You'd have to do it with triggers.
--
HTH. Ryan
"Christian Havel" <ChristianHavel@.discussions.microsoft.com> wrote in
message news:0FB2E334-A203-4BAF-BDA1-71A4462E8841@.microsoft.com...
> Hi,
> is it possible to assign a foreign key from DB1 to a primary key from DB2?
> Thanks
> Christian|||No, you have to implemt that with triggers.
BTW: Do not cross(-language) post.
HTH, jens Suessmeyer.|||Hi
You could add a check constraint that calls a function, but this is likely
to be very slow.
John
"Christian Havel" wrote:
> Hi,
> is it possible to assign a foreign key from DB1 to a primary key from DB2?
> Thanks
> Christian|||> You could add a check constraint that calls a function, but this is likely
> to be very slow.
Careful with this - real DRI works in two directions. This would only work
in one direction and only for inserts and updates.|||Scott
Both the trigger solution and the check constraint require changes to both
databases if you want to cover everything.
John
"Scott Morris" wrote:
> > You could add a check constraint that calls a function, but this is likely
> > to be very slow.
> Careful with this - real DRI works in two directions. This would only work
> in one direction and only for inserts and updates.
>
>|||> Both the trigger solution and the check constraint require changes to both
> databases if you want to cover everything.
Nothing I wrote disagreed with this. But, as I mentioned, a check
constraint is not checked during deletion. A set of triggers, when properly
designed and written, can enforce the required relationship. As far as I
know, check constraints cannot wholely support the requirement.