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* weird(to me) request
@ 2003-09-25 18:51 Larry Rosenman <ler@lerctr.org>
0 siblings, 2 replies; 5+ messages in thread
From: Larry Rosenman @ 2003-09-25 18:51 UTC (permalink / raw)
To: pgsql-sql
I have the following rows (in addition to others):
acct_num text,
master_acct_num text,
These are in the same table.
What I want to enforce is that if the master_acct_num field is NOT NULL (it
can be NULL, and
that's fine), that the value appears in some row as acct_num. acct_num has
a unique index on it, so that's fine.
I'm not sure how to do this....
Thanks!
LER
--
Larry Rosenman http://www.lerctr.org/~ler
Phone: +1 972-414-9812 E-Mail: ler@lerctr.org
US Mail: 1905 Steamboat Springs Drive, Garland, TX 75044-6749
^ permalink raw reply [nested|flat] 5+ messages in thread
* Re: weird(to me) request
@ 2003-09-25 18:59 Adam Wieckowski <adam-wieckowski@tlen.pl>
parent: Larry Rosenman <ler@lerctr.org>
1 sibling, 1 reply; 5+ messages in thread
From: Adam Wieckowski @ 2003-09-25 18:59 UTC (permalink / raw)
To: Larry Rosenman <ler@lerctr.org>; +Cc: pgsql-sql
Użytkownik Larry Rosenman napisał:
> I have the following rows (in addition to others):
>
> acct_num text,
> master_acct_num text,
>
>
> These are in the same table.
>
> What I want to enforce is that if the master_acct_num field is NOT
> NULL (it can be NULL, and
> that's fine), that the value appears in some row as acct_num.
> acct_num has a unique index on it, so that's fine.
>
> I'm not sure how to do this....
>
> Thanks!
>
> LER
>
>
select
case
when master_acct_num is null
then acct_num
else master_acct_num
end
from table;
did you mained somethink like this ?
Attachments:
smime.p7s (application/x-pkcs7-signature, 4.0K) download
^ permalink raw reply [nested|flat] 5+ messages in thread
* Re: weird(to me) request
@ 2003-09-25 19:02 Larry Rosenman <ler@lerctr.org>
parent: Adam Wieckowski <adam-wieckowski@tlen.pl>
0 siblings, 0 replies; 5+ messages in thread
From: Larry Rosenman @ 2003-09-25 19:02 UTC (permalink / raw)
To: Adam Wieckowski <adam-wieckowski@tlen.pl>; +Cc: pgsql-sql
--On Thursday, September 25, 2003 20:59:25 +0200 Adam Wieckowski
<adam-wieckowski@tlen.pl> wrote:
> U¿ytkownik Larry Rosenman napisa³:
>
>> I have the following rows (in addition to others):
>>
>> acct_num text,
>> master_acct_num text,
>>
>>
>> These are in the same table.
>>
>> What I want to enforce is that if the master_acct_num field is NOT
>> NULL (it can be NULL, and
>> that's fine), that the value appears in some row as acct_num.
>> acct_num has a unique index on it, so that's fine.
>>
>> I'm not sure how to do this....
>>
>> Thanks!
>>
>> LER
>>
>>
> select
> case
> when master_acct_num is null
> then acct_num
> else master_acct_num
> end
> from table;
>
> did you mained somethink like this ?
I'm actually looking to enforce the fact that if master_acct_num is
entered, it points
to a valid acct_num.
LER
--
Larry Rosenman http://www.lerctr.org/~ler
Phone: +1 972-414-9812 E-Mail: ler@lerctr.org
US Mail: 1905 Steamboat Springs Drive, Garland, TX 75044-6749
^ permalink raw reply [nested|flat] 5+ messages in thread
* Re: weird(to me) request
@ 2003-09-25 19:09 Richard Huxton <dev@archonet.com>
parent: Larry Rosenman <ler@lerctr.org>
1 sibling, 1 reply; 5+ messages in thread
From: Richard Huxton @ 2003-09-25 19:09 UTC (permalink / raw)
To: Larry Rosenman <ler@lerctr.org>; pgsql-sql
On Thursday 25 September 2003 19:51, Larry Rosenman wrote:
> I have the following rows (in addition to others):
>
> acct_num text,
> master_acct_num text,
>
>
> These are in the same table.
>
> What I want to enforce is that if the master_acct_num field is NOT NULL (it
> can be NULL, and
> that's fine), that the value appears in some row as acct_num. acct_num has
> a unique index on it, so that's fine.
>
> I'm not sure how to do this....
ALTER TABLE my_table ADD CONSTRAINT my_self_fk FOREIGN KEY (master_acct_num)
REFERENCES my_table (acct_num);
It's really just a foreign-key to yourself
--
Richard Huxton
Archonet Ltd
^ permalink raw reply [nested|flat] 5+ messages in thread
* Re: weird(to me) request
@ 2003-09-25 19:16 Larry Rosenman <ler@lerctr.org>
parent: Richard Huxton <dev@archonet.com>
0 siblings, 0 replies; 5+ messages in thread
From: Larry Rosenman @ 2003-09-25 19:16 UTC (permalink / raw)
To: Richard Huxton <dev@archonet.com>; pgsql-sql
--On Thursday, September 25, 2003 20:09:35 +0100 Richard Huxton
<dev@archonet.com> wrote:
> On Thursday 25 September 2003 19:51, Larry Rosenman wrote:
>> I have the following rows (in addition to others):
>>
>> acct_num text,
>> master_acct_num text,
>>
>>
>> These are in the same table.
>>
>> What I want to enforce is that if the master_acct_num field is NOT NULL
>> (it can be NULL, and
>> that's fine), that the value appears in some row as acct_num. acct_num
>> has a unique index on it, so that's fine.
>>
>> I'm not sure how to do this....
>
> ALTER TABLE my_table ADD CONSTRAINT my_self_fk FOREIGN KEY
> (master_acct_num) REFERENCES my_table (acct_num);
>
> It's really just a foreign-key to yourself
I wasn't sure I could do that. Thanks!
LER
--
Larry Rosenman http://www.lerctr.org/~ler
Phone: +1 972-414-9812 E-Mail: ler@lerctr.org
US Mail: 1905 Steamboat Springs Drive, Garland, TX 75044-6749
^ permalink raw reply [nested|flat] 5+ messages in thread
end of thread, other threads:[~2003-09-25 19:16 UTC | newest]
Thread overview: 5+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2003-09-25 18:51 weird(to me) request Larry Rosenman <ler@lerctr.org>
2003-09-25 18:59 ` Adam Wieckowski <adam-wieckowski@tlen.pl>
2003-09-25 19:02 ` Larry Rosenman <ler@lerctr.org>
2003-09-25 19:09 ` Richard Huxton <dev@archonet.com>
2003-09-25 19:16 ` Larry Rosenman <ler@lerctr.org>
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