Axel Rau wrote:
> Hi SQLers,
>
> I have a fk from address to network and try to update the foreign key
> column to point at the network, "it belongs to":
>
> CREATE TABLE network (
> id cidr PRIMARY KEY , -- 'PK, ,IPv4/6 Network address'
> )
>
> CREATE TABLE address (
> id inet PRIMARY KEY , -- 'PK of IPv4/6 host address'
> network cidr NOT NULL -- 'FK to Network table'
> REFERENCES network ON DELETE CASCADE ON UPDATE
> CASCADE
> )
>
> I tried (using the WHERE clause to eliminate the addresses were no
> corresponding net exists):
But you can't insert a row in address w/o a valid network.id? That's
what the fk ensures.
Perhaps you could elaborate more? Are you trying to *put* on the fk and
you currently have bad data?
> UPDATE address
> SET network = (SELECT N.id WHERE A.id << N.id)
> FROM address A, network N
> WHERE A.id << N.id;
>
This also makes no sense. For starters, << is "bitwise shift left" ...
> But this ended up with all network columns pointing at the same net (-:).
> Any help would be appreciated.
>
> Axel
> Axel Rau, Frankfurt, Germany +49-69-951418-0
>
>
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> TIP 9: In versions below 8.0, the planner will ignore your desire to
> choose an index scan if your joining column's datatypes do not
> match
--
Daryl
"We want great men who, when fortune frowns, will not be discouraged." -- Colonel Henry Knox, 1776
