jsr338-experts@jpa-spec.java.net

[jsr338-experts] Re: outer joins with ON conditions

From: Emmanuel Bernard <emmanuel.bernard_at_jboss.com>
Date: Tue, 15 Mar 2011 18:55:47 +0100

On 15 mars 2011, at 17:51, Linda DeMichiel wrote:

>
> On 3/15/2011 3:31 AM, Emmanuel Bernard wrote:
>> The doc is minimal, I'm pasting it for info
>> You may supply extra join conditions using the HQL with keyword.
>> from Cat as cat
>> left join cat.kittens as kitten
>> with kitten.bodyWeight > 10.0
>> <<<
>> http://docs.jboss.org/hibernate/core/3.6/reference/en-US/html/queryhql.html#queryhql-joins
>> this essentially concatenate an SQL version of kitten.bodyWeight > 10.0 to the rest of the SQL ON clause used to auto join the Cat table.
>> My email was really a question, I wanted to confirm that what you were proposing was essentially the same concept.
>
> Thanks -- yes.
>
>> As for a full ON clause replacement, a few users and customers have requested it over the years. But we have not implemented such a feature yet. I suspect people are willing to do adhoc joins even across non mapped associations. I see it as much less useful than the proposed feature.
>
> Same here. We could add it later if requested.

OK nice. So the reason for proposing a different keyword than ON for the "add-on" ON clause was to leave the door open for the full fledge ON replacement. In Hibernate we use WITH.

Emmanuel