Обсуждение: Update ordered

On 01/27/2014 06:36 AM, Andreas Joseph Krogh wrote:
> Hi all.
> I want an UPDATE query to update my project's project_number in
> chronological order (according to the project's "created"-column) and
> tried this:
> with upd as(
>      select id from project order by created asc
> ) update project p set project_number = get_next_project_number() from
> upd where upd.id = p.id;
> However, the olders project doesn't get the smalles project_number.
> Any idea how to achive this?

That would seem to depend on what get_next_project_number() does, the 
contents of which are unknown.

> Thanks.
> --
> Andreas Joseph Krogh <andreak@officenet.no>      mob: +47 909 56 963
> Senior Software Developer / CTO - OfficeNet AS - http://www.officenet.no
> Public key: http://home.officenet.no/~andreak/public_key.asc


-- 
Adrian Klaver
adrian.klaver@gmail.com

On 01/27/2014 06:36 AM, Andreas Joseph Krogh wrote:
> Hi all.
> I want an UPDATE query to update my project's project_number in
> chronological order (according to the project's "created"-column) and
> tried this:
> with upd as(
>      select id from project order by created asc
> ) update project p set project_number = get_next_project_number() from
> upd where upd.id = p.id;
> However, the olders project doesn't get the smalles project_number.
> Any idea how to achive this?

That would seem to depend on what get_next_project_number() does, the
contents of which are unknown.

On 01/27/2014 07:01 AM, Andreas Joseph Krogh wrote:
> På mandag 27. januar 2014 kl. 15:56:12, skrev Adrian Klaver
> <adrian.klaver@gmail.com <mailto:adrian.klaver@gmail.com>>:
>
>     On 01/27/2014 06:36 AM, Andreas Joseph Krogh wrote:
>      > Hi all.
>      > I want an UPDATE query to update my project's project_number in
>      > chronological order (according to the project's "created"-column) and
>      > tried this:
>      > with upd as(
>      >      select id from project order by created asc
>      > ) update project p set project_number = get_next_project_number()
>     from
>      > upd where upd.id = p.id;
>      > However, the olders project doesn't get the smalles project_number.
>      > Any idea how to achive this?
>
>     That would seem to depend on what get_next_project_number() does, the
>     contents of which are unknown.
>
> get_next_project_number() gets the next project-number based on some
> custom logic.
> What would be the best way to update all project's project-number having
> the oldes project get the first number returned by
> get_next_project_number() etc.?

How are you sure it is not, have you tried something like below to test?:

with upd as(    select id from project order by created asc
) select p.id, p.create from project_number where upd.id = p.id;

> Thanks.
> --
> Andreas Joseph Krogh <andreak@officenet.no>      mob: +47 909 56 963
> Senior Software Developer / CTO - OfficeNet AS - http://www.officenet.no
> Public key: http://home.officenet.no/~andreak/public_key.asc


-- 
Adrian Klaver
adrian.klaver@gmail.com

On 01/27/2014 07:01 AM, Andreas Joseph Krogh wrote:
> På mandag 27. januar 2014 kl. 15:56:12, skrev Adrian Klaver
> <adrian.klaver@gmail.com <mailto:adrian.klaver@gmail.com>>:
>
>     On 01/27/2014 06:36 AM, Andreas Joseph Krogh wrote:
>      > Hi all.
>      > I want an UPDATE query to update my project's project_number in
>      > chronological order (according to the project's "created"-column) and
>      > tried this:
>      > with upd as(
>      >      select id from project order by created asc
>      > ) update project p set project_number = get_next_project_number()
>     from
>      > upd where upd.id = p.id;
>      > However, the olders project doesn't get the smalles project_number.
>      > Any idea how to achive this?
>
>     That would seem to depend on what get_next_project_number() does, the
>     contents of which are unknown.
>
> get_next_project_number() gets the next project-number based on some
> custom logic.
> What would be the best way to update all project's project-number having
> the oldes project get the first number returned by
> get_next_project_number() etc.?

How are you sure it is not, have you tried something like below to test?:

with upd as(
     select id from project order by created asc
) select p.id, p.create from project_number where upd.id = p.id;

On 01/27/2014 07:37 AM, Andreas Joseph Krogh wrote:

>      > get_next_project_number() etc.?
>
>     How are you sure it is not, have you tried something like below to
>     test?:
>
>     with upd as(
>           select id from project order by created asc
>     ) select p.id, p.create from project_number where upd.id = p.id;
>
> Yes, that returns ordered result, but the update CTE doens't update with
> the oldest project getting the first sequenc-nr.
> Using a DO statement, iterating over all projects ordered by "created"
> then updating each project matching the current iteration works, but I'd
> like to be able to do it in one statement as I'm sure it's possible...

Well two things;

1) Knowing what is in get_next_project_number() would be helpful?

2) Absent the above I do not see how:

update project p set project_number = get_next_project_number() from upd 
where upd.id = p.id;

will actually work. No argument is being passed to 
get_next_project_number() so I am not sure how it picks up what 
id/created or other reference it is actually working with.

This is borne out by your success using a DO where in the iteration you 
do match.

> --
> Andreas Joseph Krogh <andreak@officenet.no>      mob: +47 909 56 963
> Senior Software Developer / CTO - OfficeNet AS - http://www.officenet.no
> Public key: http://home.officenet.no/~andreak/public_key.asc


-- 
Adrian Klaver
adrian.klaver@gmail.com

On 27/01/2014 16:36, Andreas Joseph Krogh wrote:
> Hi all.
> I want an UPDATE query to update my project's project_number in chronological order (according to the project's
"created"-column)and tried this:
 
> with upd as(
>     select id from project order by created asc
> ) update project p set project_number = get_next_project_number() from upd where upd.id = p.id;
> However, the olders project doesn't get the smalles project_number.

I think that makes sense. When you UPDATE ... FROM an another relation, nothing is guaranteed
about the order of the from_list join. Therefore "order by created asc" in your CTE is not gonna
achieve much.

Your better write this as a procedure. (as you have already suggested)

> Any idea how to achive this?
> Thanks.
> --
> Andreas Joseph Krogh <andreak@officenet.no>      mob: +47 909 56 963
> Senior Software Developer / CTO - OfficeNet AS - http://www.officenet.no
> Public key: http://home.officenet.no/~andreak/public_key.asc


-- 
Achilleas Mantzios
Head of IT DEV
IT DEPT
Dynacom Tankers Mgmt