RE: Collection or list as return ??
We used ORDER BY in the finder method query in Orion 1.3.8 with no problems, then moved to Orion 1.5.2 and they stopped working. Check which version of Orion you're using. -Original Message- From: Eddie Post [mailto:[EMAIL PROTECTED]] Sent: 15 June 2001 23:48 To: Orion-Interest Subject: Re: Collection or list as return ?? Thanks Scott, Thanks for the test (stupid that I didn't thought about that ;) ). So, yes the returned Collection (read: ArrayList) is a sorted one. But how general is this, as I can't find anything in the J2EE spec about this and is it possible that Orion will change this such that it isn't sorted anymore ? What do you think ? Let the DB do the order by or just let the sort method of Collections do the trick ? I have noticed that the sort method is very fast. Eddie
RE: Collection or list as return ??
Thanks jeff for clearing this up.
I will let the program order my collection.
I already have defined about 10 own finders in orion-ejb-jar.xml (otherwise
it becomes to slow), so the application is already binded to orion and not
fully J2EE compliant, but to also let the Db do the sort trick... Hmmm I
little bit to much I think...
Eddie
From: Jeff Schnitzer [EMAIL PROTECTED]
Reply-To: Orion-Interest [EMAIL PROTECTED]
To: Orion-Interest [EMAIL PROTECTED]
Subject: RE: Collection or list as return ??
Date: Fri, 15 Jun 2001 16:57:20 -0700
You're right, there is no guarantee from the spec that other app servers
will return data in order or even allow you to specify the ORDER BY
clause in the finder sql. For that matter, there is no guarantee that
the database has a sql interface.
It gets even worse. The current spec for EJB-QL has no support for
ordering. The *only* way to write a 100% spec-compliant app which does
ordering is to implement the sorting yourself, in application code, in
Java.
It's pretty obvious to me at least that the people developing the EJB
specification have never actually used their ideas to develop a real
world application. Fortunately for us, container vendors are less
insulated from the eventual customers; it's a pretty safe bet that most
servers will let you configure the ordering in the database query
somehow. I wouldn't worry about it, but no, it's not standard.
Jeff Schnitzer
-Original Message-
From: Eddie Post [mailto:[EMAIL PROTECTED]]
Sent: Friday, June 15, 2001 3:48 PM
To: Orion-Interest
Subject: Re: Collection or list as return ??
Thanks Scott,
Thanks for the test (stupid that I didn't thought about that
;) ). So, yes
the returned Collection (read: ArrayList) is a sorted one.
But how general is this, as I can't find anything in the J2EE
spec about
this and is it possible that Orion will change this such that
it isn't
sorted anymore ?
What do you think ? Let the DB do the order by or just let
the sort method
of Collections do the trick ? I have noticed that the sort
method is very
fast.
Eddie
From: Scot Weber [EMAIL PROTECTED]
Reply-To: Orion-Interest [EMAIL PROTECTED]
To: Orion-Interest [EMAIL PROTECTED]
Subject: Re: Collection or list as return ??
Date: Fri, 15 Jun 2001 12:15:46 -0700
Eddie,
I just tested it . . .
MyTestHome.java __
public interface MyTestHome {
public Collection findAll () ...
}
mytest.jsp__
%= myTestHome.findall ().getClass () %
output_
java.util.ArrayList
peace - scot
Eddie wrote:
Hellu there,
Some time ago someone made a remark that it make no sense
putting a
ORDER
BY in the where clause in the orion-ejb-jar.xml, as the finder
methods of
the home interface do return a Collection, which are not sorted by
definition.
Hmmm makes sence, but if I play around with it and put a
ORDER BY id
ASC
or ORDER BY id DESC in the where clause in the
orion-ejb-jar.xml, to
fine
tune some queries, it does return sorted collections
Howcome ?? Does the finder methods return a sorted List as a J2EE
feature,
that is a subClass of a Collection, or is this just Orion. ??
The thing is that I like to optimize my queries, but if
this feature
isn't
J2EE for example I will have a problem with the following
upgrades if
it's
left out for some reason !!
BTW: in the J2EE spec, in section 10.5.6 they only talk about the
Collection
data type.!!
Some advise please ??
Eddie
--
scot weber - [EMAIL PROTECTED]
-
Given a choice between a folly and a sacrament, one should
always choose the folly -- because we know a sacrament
will not bring us closer to God and there's always a chance
that a folly will. - Erasmus
The only man who never makes a mistake is the man who
never does anything. - Theodore Roosevelt.
__
___
Get Your Private, Free E-mail from MSN Hotmail at
http://www.hotmail.com.
_
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.
Re: Collection or list as return ??
Eddie, java.util.Collection is an interface, so chances are the real container is a java.util.ArrayList, which is linearly sequential. I don't know this to be a fact, but it's just a thought . . . - Scot Eddie wrote: Hellu there, Some time ago someone made a remark that it make no sense putting a ORDER BY in the where clause in the orion-ejb-jar.xml, as the finder methods of the home interface do return a Collection, which are not sorted by definition. Hmmm makes sence, but if I play around with it and put a ORDER BY id ASC or ORDER BY id DESC in the where clause in the orion-ejb-jar.xml, to fine tune some queries, it does return sorted collections Howcome ?? Does the finder methods return a sorted List as a J2EE feature, that is a subClass of a Collection, or is this just Orion. ?? The thing is that I like to optimize my queries, but if this feature isn't J2EE for example I will have a problem with the following upgrades if it's left out for some reason !! BTW: in the J2EE spec, in section 10.5.6 they only talk about the Collection data type.!! Some advise please ?? Eddie -- scot weber - [EMAIL PROTECTED] - Given a choice between a folly and a sacrament, one should always choose the folly -- because we know a sacrament will not bring us closer to God and there's always a chance that a folly will. - Erasmus The only man who never makes a mistake is the man who never does anything. - Theodore Roosevelt.
Re: Collection or list as return ??
Eddie,
I just tested it . . .
MyTestHome.java __
public interface MyTestHome {
public Collection findAll () ...
}
mytest.jsp__
%= myTestHome.findall ().getClass () %
output_
java.util.ArrayList
peace - scot
Eddie wrote:
Hellu there,
Some time ago someone made a remark that it make no sense putting a
ORDER
BY in the where clause in the orion-ejb-jar.xml, as the finder
methods of
the home interface do return a Collection, which are not sorted by
definition.
Hmmm makes sence, but if I play around with it and put a ORDER BY id
ASC
or ORDER BY id DESC in the where clause in the orion-ejb-jar.xml, to
fine
tune some queries, it does return sorted collections
Howcome ?? Does the finder methods return a sorted List as a J2EE
feature,
that is a subClass of a Collection, or is this just Orion. ??
The thing is that I like to optimize my queries, but if this feature
isn't
J2EE for example I will have a problem with the following upgrades if
it's
left out for some reason !!
BTW: in the J2EE spec, in section 10.5.6 they only talk about the
Collection
data type.!!
Some advise please ??
Eddie
--
scot weber - [EMAIL PROTECTED]
-
Given a choice between a folly and a sacrament, one should
always choose the folly -- because we know a sacrament
will not bring us closer to God and there's always a chance
that a folly will. - Erasmus
The only man who never makes a mistake is the man who
never does anything. - Theodore Roosevelt.
Re: Collection or list as return ??
Thanks Scott,
Thanks for the test (stupid that I didn't thought about that ;) ). So, yes
the returned Collection (read: ArrayList) is a sorted one.
But how general is this, as I can't find anything in the J2EE spec about
this and is it possible that Orion will change this such that it isn't
sorted anymore ?
What do you think ? Let the DB do the order by or just let the sort method
of Collections do the trick ? I have noticed that the sort method is very
fast.
Eddie
From: Scot Weber [EMAIL PROTECTED]
Reply-To: Orion-Interest [EMAIL PROTECTED]
To: Orion-Interest [EMAIL PROTECTED]
Subject: Re: Collection or list as return ??
Date: Fri, 15 Jun 2001 12:15:46 -0700
Eddie,
I just tested it . . .
MyTestHome.java __
public interface MyTestHome {
public Collection findAll () ...
}
mytest.jsp__
%= myTestHome.findall ().getClass () %
output_
java.util.ArrayList
peace - scot
Eddie wrote:
Hellu there,
Some time ago someone made a remark that it make no sense putting a
ORDER
BY in the where clause in the orion-ejb-jar.xml, as the finder
methods of
the home interface do return a Collection, which are not sorted by
definition.
Hmmm makes sence, but if I play around with it and put a ORDER BY id
ASC
or ORDER BY id DESC in the where clause in the orion-ejb-jar.xml, to
fine
tune some queries, it does return sorted collections
Howcome ?? Does the finder methods return a sorted List as a J2EE
feature,
that is a subClass of a Collection, or is this just Orion. ??
The thing is that I like to optimize my queries, but if this feature
isn't
J2EE for example I will have a problem with the following upgrades if
it's
left out for some reason !!
BTW: in the J2EE spec, in section 10.5.6 they only talk about the
Collection
data type.!!
Some advise please ??
Eddie
--
scot weber - [EMAIL PROTECTED]
-
Given a choice between a folly and a sacrament, one should
always choose the folly -- because we know a sacrament
will not bring us closer to God and there's always a chance
that a folly will. - Erasmus
The only man who never makes a mistake is the man who
never does anything. - Theodore Roosevelt.
_
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.
RE: Collection or list as return ??
You're right, there is no guarantee from the spec that other app servers
will return data in order or even allow you to specify the ORDER BY
clause in the finder sql. For that matter, there is no guarantee that
the database has a sql interface.
It gets even worse. The current spec for EJB-QL has no support for
ordering. The *only* way to write a 100% spec-compliant app which does
ordering is to implement the sorting yourself, in application code, in
Java.
It's pretty obvious to me at least that the people developing the EJB
specification have never actually used their ideas to develop a real
world application. Fortunately for us, container vendors are less
insulated from the eventual customers; it's a pretty safe bet that most
servers will let you configure the ordering in the database query
somehow. I wouldn't worry about it, but no, it's not standard.
Jeff Schnitzer
-Original Message-
From: Eddie Post [mailto:[EMAIL PROTECTED]]
Sent: Friday, June 15, 2001 3:48 PM
To: Orion-Interest
Subject: Re: Collection or list as return ??
Thanks Scott,
Thanks for the test (stupid that I didn't thought about that
;) ). So, yes
the returned Collection (read: ArrayList) is a sorted one.
But how general is this, as I can't find anything in the J2EE
spec about
this and is it possible that Orion will change this such that
it isn't
sorted anymore ?
What do you think ? Let the DB do the order by or just let
the sort method
of Collections do the trick ? I have noticed that the sort
method is very
fast.
Eddie
From: Scot Weber [EMAIL PROTECTED]
Reply-To: Orion-Interest [EMAIL PROTECTED]
To: Orion-Interest [EMAIL PROTECTED]
Subject: Re: Collection or list as return ??
Date: Fri, 15 Jun 2001 12:15:46 -0700
Eddie,
I just tested it . . .
MyTestHome.java __
public interface MyTestHome {
public Collection findAll () ...
}
mytest.jsp__
%= myTestHome.findall ().getClass () %
output_
java.util.ArrayList
peace - scot
Eddie wrote:
Hellu there,
Some time ago someone made a remark that it make no sense
putting a
ORDER
BY in the where clause in the orion-ejb-jar.xml, as the finder
methods of
the home interface do return a Collection, which are not sorted by
definition.
Hmmm makes sence, but if I play around with it and put a
ORDER BY id
ASC
or ORDER BY id DESC in the where clause in the
orion-ejb-jar.xml, to
fine
tune some queries, it does return sorted collections
Howcome ?? Does the finder methods return a sorted List as a J2EE
feature,
that is a subClass of a Collection, or is this just Orion. ??
The thing is that I like to optimize my queries, but if
this feature
isn't
J2EE for example I will have a problem with the following
upgrades if
it's
left out for some reason !!
BTW: in the J2EE spec, in section 10.5.6 they only talk about the
Collection
data type.!!
Some advise please ??
Eddie
--
scot weber - [EMAIL PROTECTED]
-
Given a choice between a folly and a sacrament, one should
always choose the folly -- because we know a sacrament
will not bring us closer to God and there's always a chance
that a folly will. - Erasmus
The only man who never makes a mistake is the man who
never does anything. - Theodore Roosevelt.
__
___
Get Your Private, Free E-mail from MSN Hotmail at
http://www.hotmail.com.
