[Zach Dennis]

Hello, Welcome to the list!

Zach

-----Original Message-----
From: Jean-Christophe Choisy [mailto:closedb@nothus.org]
Sent: Monday, November 17, 2003 9:35 PM
To: ruby-talk ML
Subject:


Hi everyone! New to Ruby, New to this mailing list... Just felt like
saying hello...
later!

--
CloseDB ~~ nothus.org

[Peter Hickman]

Jesper Olsen wrote:

> I am currently using ruby's mysql extention.
> Recently PostgreSql has become available to me also.
>
> PostgreSql is not part of the ruby distribution, but I notice that
> there is an extention available for it:
>
> [url]http://www.postgresql.jp/interfaces/ruby/reference.html[/url]
>
> I think the Ruby API's are more or less the same?
>
> Maybe this not strictly a ruby question, but can anyone here comment on
> how MySQL and PostgreSQL compare?
> Is PostgreSQL in any way better than MySql - ie. faster or more stable.
>
> Cheers
> Jesper
>
>
> --
> [url]http://JesperOlsen.Net[/url]
>
>

PostgreSQL has stored procedures and MySQL doesn't (although a new derived
version of MySQL does - recently announced, I know nothing about it).

I think PostgreSQL also has constraints and triggers that MySQL doesn't /
might not have.

We use PostgreSQL but for your needs (whatever they are) MySQL could be perfect.

Haven't used MySQL in a few years but I liked it when I used it.

[kglad]

check your previous post and please don't post duplicate (no pun intended) threads.

[John Sidney-Woollett]

Useful to add a title to your messages before you post...

How about:

select parentid, count(*) as number_of_children
from childtable
group by parentid
order by parentid;

If there are parent records that have no children then these will be
omitted. The query above totally ignores the parent table (which you may
not want it to do).

John Sidney-Woollett

Joost Kraaijeveld wrote:

> Hi all,
>
> Is it possible to count and display the number of children of a parent in a generic query?
>
>
> parent table: id
> child table: id, parent_id
>
> Example output of the query:
>
> parentid number_of_children
> parent1 2
> parent2 6
> parent3 0
>
>
>
> Groeten,
>
> Joost Kraaijeveld
> Askesis B.V.
> Molukkenstraat 14
> 6524NB Nijmegen
> tel: 024-3888063 / 06-51855277
> fax: 024-3608416
> e-mail: [email]J.Kraaijeveld@Askesis.nl[/email]
> web: [url]www.askesis.nl[/url]
>
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[TangoRules]

Sorry, don't mean to submit my post twice. When I submitted my post, I got a
ColdFusion error saying 441 437 Missing Subject.. I thought it didn't get
submitted and so I clicked back to submit again. And I got the same error
message again.

But anyway, sorry for posting my article twice.