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From "Andy Jefferson (JIRA)" <j...@apache.org>
Subject [jira] Commented: (JDO-637) JDOQL : Enhance the JDOQL with JOIN and ALIAS features
Date Tue, 28 Jul 2009 12:25:14 GMT

    [ https://issues.apache.org/jira/browse/JDO-637?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12736047#action_12736047
] 

Andy Jefferson commented on JDO-637:
------------------------------------

Isn't the point supposed to be that JDOQL is Java syntax. Just adopting JPQL syntax doesn't
seem to fit in with that goal to me. "INNER JOIN", "LEFT OUTER JOIN" don't mean a great deal
for such as an XML datastore, or LDAP. 
In general terms, when applying it to an RDBMS context, the type of relation and its nullability
would define whether or not to use INNER JOIN or LEFT OUTER JOIN.

If wishing to use JPQL, any implementation can provide it using the same JDO API query mechanism
(and some do).

> JDOQL : Enhance the JDOQL with JOIN and ALIAS features 
> -------------------------------------------------------
>
>                 Key: JDO-637
>                 URL: https://issues.apache.org/jira/browse/JDO-637
>             Project: JDO
>          Issue Type: New Feature
>          Components: api2
>            Reporter: Eric SULTAN
>
> JOIN examples :
> SELECT this.x, this,y, this.b.z FROM package.A JOIN this.b 
> SELECT this.x, this,y, this.b.z FROM package.A LEFT OUTER JOIN this.b 
> ALIAS examples :
> SELECT alias1.x, alias1.y, alias1.b.z FROM package.A alias1 WHERE alias1.number >
10
> JOIN and ALIAS examples :
> SELECT alias1.x, alias1.y, alias1.b.z FROM package.A alias1 LEFT OUTER JOIN alias1.b
WHERE alias1.number > 10
> SELECT alias1.x, alias1.y, alias2.z FROM package.A alias1 LEFT OUTER JOIN alias1.b alias2
WHERE alias1.number > 10

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