db-jdo-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From <e...@jpox.org>
Subject RE: Negative [VOTE] Issue 149: Restrictions on Ordering expression used with Grouping
Date Sat, 24 Dec 2005 09:20:10 GMT
Thanks for the clarification
 
Erik Bengtson
-----Original Message-----
From: Craig.Russell@Sun.COM [mailto:Craig.Russell@Sun.COM] 
Sent: Saturday, December 24, 2005 4:26 AM
To: Apache JDO project; JDO Expert Group
Subject: Re: Negative [VOTE] Issue 149: Restrictions on Ordering
expression used with Grouping
 
Hi Erik,
 
I think we actually agree, and the wording of my proposal was poor.
 
On Dec 22, 2005, at 5:48 AM, erik@jpox.org wrote:



-1.
 
In order, I prefer adding columns in SQL (SELECT) as appropriate, but
only
returning to the user the columns/fields listed in setResult.
 
I agree. Exactly what I meant to say. This:
 
However, the JDO implementation is required to construct valid SQL
if the query is being used with a relational datastore. This means
that the SQL SELECT might need to have expressions added to the
user's Select clause to include expressions in the Grouping and
Ordering clauses.
 
should have said this:
 
However, the JDO implementation is required to construct valid SQL
if the query is being used with a relational datastore. This means
that the SQL SELECT might need to have expressions that are not in the
user's Select clause to include expressions in the Grouping and
Ordering clauses. These expressions are not returned to the user.
 
Ok?
 
Craig


 
For grouping, I'm ok with raising an exception when expressions are not
declared
by user
 
Regards,
 
Quoting Craig L Russell <Craig.Russell@Sun.COM>:
 
Javadogs,
 
Please reply if you do not agree.
 
Craig
 
On Dec 19, 2005, at 11:25 AM, Craig L Russell wrote:
 
Javadogs,
 
See JIRA issue JDO-243 http://issues.apache.org/jira/browse/JDO-243?
page=all
Ordering should have the same restrictions as for the Select
clause. That is, if grouping is used, only expressions in the
Grouping clause and aggregate expressions can be in the Ordering
clause.
The JDO implementation is not permitted to modify the Select
clause, the Grouping clause, or the Ordering clause. These are user-
visible and should not be changed by the implementation.
However, the JDO implementation is required to construct valid SQL
if the query is being used with a relational datastore. This means
that the SQL SELECT might need to have expressions added to the
user's Select clause to include expressions in the Grouping and
Ordering clauses.
Today in the specification there are restrictions on the
expressions that can be used in the Select clause if there is a
Grouping clause:
<spec 14.6.10>
Only expressions in the Grouping clause and aggregate expressions
can be in the Select clause.
</spec 14.6.10>
A similar restriction is needed for the Ordering clause.
<proposed>
Only expressions in the Grouping clause and aggregate expressions
can be in the Ordering clause.
</proposed>
 
Craig Russell
Architect, Sun Java Enterprise System http://java.sun.com/products/jdo
408 276-5638 mailto:Craig.Russell@sun.com
P.S. A good JDO? O, Gasp!
 
 
Craig Russell
Architect, Sun Java Enterprise System http://java.sun.com/products/jdo
408 276-5638 mailto:Craig.Russell@sun.com
P.S. A good JDO? O, Gasp!
 
 
 
 
 
 
Craig Russell
Architect, Sun Java Enterprise System http://java.sun.com/products/jdo
408 276-5638 mailto:Craig.Russell@sun.com
P.S. A good JDO? O, Gasp!
 

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message