agora inbox for pgsql-sql@postgresql.org
help / color / mirror / Atom feedunique key problem on update
4+ messages / 2 participants
[nested] [flat]
* unique key problem on update
@ 2013-09-20 16:07 Gary Stainburn <gary.stainburn@ringways.co.uk>
2013-09-20 16:26 ` Re: unique key problem on update Thomas Kellerer <spam_eater@gmx.net>
0 siblings, 1 reply; 4+ messages in thread
From: Gary Stainburn @ 2013-09-20 16:07 UTC (permalink / raw)
To: pgsql-sql
Hi folks.
I've got the table and data shown below.
I want to add a new page after page 2 so I try to increase the sequence number
of each row from page 3 onwards to make space in the sequence for the new
record. However, I get duplicate key errors when I try. Can anyone suggest
how I get round this.
Also, the final version will be put onto a WordPress web site which means I
will have to port it to MYSQL which I don't know, so any solution that will
work with both systems would be a great help.
Ta
Gary
stainburn=# \d skills_pages
Table "public.skills_pages"
Column | Type | Modifiers
-------------+-----------------------+--------------------------------------------------------------
sp_id | integer | not null default
nextval('skills_pages_sp_id_seq'::regclass)
sp_sequence | integer | not null
sp_title | character varying(80) |
sp_narative | text |
Indexes:
"skills_pages_pkey" PRIMARY KEY, btree (sp_id)
"skills_pages_sequence" UNIQUE, btree (sp_sequence)
stainburn=# select * from skills_pages;
sp_id | sp_sequence | sp_title | sp_narative
-------+-------------+------------------+-------------
1 | 10 | Departments |
2 | 20 | Interest Groups |
3 | 30 | Customer Focused |
4 | 40 | Business Roles |
5 | 50 | Commercial |
6 | 60 | People Oriented |
7 | 70 | Engineering |
(7 rows)
stainburn=# update skills_pages set sp_sequence=sp_sequence+10 where
sp_sequence >= 30;
ERROR: duplicate key value violates unique constraint "skills_pages_sequence"
stainburn=#
--
Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-sql
^ permalink raw reply [nested|flat] 4+ messages in thread
* Re: unique key problem on update
2013-09-20 16:07 unique key problem on update Gary Stainburn <gary.stainburn@ringways.co.uk>
@ 2013-09-20 16:26 ` Thomas Kellerer <spam_eater@gmx.net>
2013-09-20 16:30 ` Re: unique key problem on update Gary Stainburn <gary.stainburn@ringways.co.uk>
0 siblings, 1 reply; 4+ messages in thread
From: Thomas Kellerer @ 2013-09-20 16:26 UTC (permalink / raw)
To: pgsql-sql
Gary Stainburn wrote on 20.09.2013 18:07:
> I want to add a new page after page 2 so I try to increase the sequence number
> of each row from page 3 onwards to make space in the sequence for the new
> record. However, I get duplicate key errors when I try. Can anyone suggest
> how I get round this.
>
> Also, the final version will be put onto a WordPress web site which means I
> will have to port it to MYSQL which I don't know, so any solution that will
> work with both systems would be a great help.
>
You need to define the primary key as deferrable:
create table skills_pages
(
sp_id serial not null,
sp_sequence integer not null,
sp_title character varying(80),
sp_narative text,
primary key (sp_id) deferrable
);
--
Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-sql
^ permalink raw reply [nested|flat] 4+ messages in thread
* Re: unique key problem on update
2013-09-20 16:07 unique key problem on update Gary Stainburn <gary.stainburn@ringways.co.uk>
2013-09-20 16:26 ` Re: unique key problem on update Thomas Kellerer <spam_eater@gmx.net>
@ 2013-09-20 16:30 ` Gary Stainburn <gary.stainburn@ringways.co.uk>
2013-09-20 16:42 ` Re: unique key problem on update Thomas Kellerer <spam_eater@gmx.net>
0 siblings, 1 reply; 4+ messages in thread
From: Gary Stainburn @ 2013-09-20 16:30 UTC (permalink / raw)
To: pgsql-sql; +Cc: Thomas Kellerer <spam_eater@gmx.net>
On Friday 20 September 2013 17:26:58 Thomas Kellerer wrote:
> You need to define the primary key as deferrable:
>
> create table skills_pages
> (
> sp_id serial not null,
> sp_sequence integer not null,
> sp_title character varying(80),
> sp_narative text,
> primary key (sp_id) deferrable
> );
Cheers. I'll look at that. It's actually the second unique index that's the
problem but I'm guessing I can set that index up as deferrable too.
Hopefully it'll work for mysql too.
--
Gary Stainburn
Group I.T. Manager
Ringways Garages
http://www.ringways.co.uk
--
Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-sql
^ permalink raw reply [nested|flat] 4+ messages in thread
* Re: unique key problem on update
2013-09-20 16:07 unique key problem on update Gary Stainburn <gary.stainburn@ringways.co.uk>
2013-09-20 16:26 ` Re: unique key problem on update Thomas Kellerer <spam_eater@gmx.net>
2013-09-20 16:30 ` Re: unique key problem on update Gary Stainburn <gary.stainburn@ringways.co.uk>
@ 2013-09-20 16:42 ` Thomas Kellerer <spam_eater@gmx.net>
0 siblings, 0 replies; 4+ messages in thread
From: Thomas Kellerer @ 2013-09-20 16:42 UTC (permalink / raw)
To: pgsql-sql
Gary Stainburn wrote on 20.09.2013 18:30:
>> You need to define the primary key as deferrable:
>>
>> create table skills_pages
>> (
>> sp_id serial not null,
>> sp_sequence integer not null,
>> sp_title character varying(80),
>> sp_narative text,
>> primary key (sp_id) deferrable
>> );
>
> Cheers. I'll look at that. It's actually the second unique index that's the
> problem but I'm guessing I can set that index up as deferrable too.
Ah, sorry didn't see that ;) but, yes it works the same way:
create table skills_pages
(
sp_id serial not null,
sp_sequence integer not null,
sp_title character varying(80),
sp_narative text,
primary key (sp_id),
unique (sp_sequence) deferrable
);
> Hopefully it'll work for mysql too.
No, it won't.
MySQL neither has deferrable constraints nor does it evaluate them on statement level (they are *always* evaluated row-by-row).
--
Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-sql
^ permalink raw reply [nested|flat] 4+ messages in thread
end of thread, other threads:[~2013-09-20 16:42 UTC | newest]
Thread overview: 4+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2013-09-20 16:07 unique key problem on update Gary Stainburn <gary.stainburn@ringways.co.uk>
2013-09-20 16:26 ` Thomas Kellerer <spam_eater@gmx.net>
2013-09-20 16:30 ` Gary Stainburn <gary.stainburn@ringways.co.uk>
2013-09-20 16:42 ` Thomas Kellerer <spam_eater@gmx.net>
This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox