Found the trouble... if you JOIN, you have to alias:
JOIN foo.bar bar JOIN bar.baz baz
Also, the trouble with the lazy loading was that I'd closed the
EntityManager before trying to get at a lazy-loaded field, so naturally
that wasn't gonna work...
On Sun, 11 Nov 2007, Nick Johnson wrote:
> First, are multiple JOIN clauses supported? (Sanity check)
>
> I have a set of classes, BinaryResourceReference, BinaryResourceLocale and
> BinaryResourceContent. One BinaryResourceReference may have many
> BinaryResourceLocales, and each BinaryResourceLocale has one
> BinaryResourceContent.
>
> I find that if I do a JPA query for BinaryResourceReference and JOIN FETCH
> its BinaryResourceLocales, then the content field of each
> BinaryResourceLocale is null and won't be lazy-loaded.
>
> If I take another approach and try to join all the way through, with this
> query:
>
> SELECT ref FROM BinaryResourceReference ref JOIN ref.locales locales
> JOIN locales.content WHERE ref.scope = ?1 AND ref.path = ?2 AND
> ref.extension = ?3
>
> then I get this exception:
>
> Caused by: <openjpa-1.0.0-r420667:568756 nonfatal user error>
> org.apache.openjpa.persistence.ArgumentException: Encountered "JOIN
> locales . content WHERE" at character 70, but expected: [".", "ABS",
> "ALL", "AND", "ANY", "AS", "ASC", "AVG", "BETWEEN", "BOTH", "BY",
> "CONCAT", "COUNT", "CURRENT_DATE", "CURRENT_TIME", "CURRENT_TIMESTAMP",
> "DELETE", "DESC", "DISTINCT", "EMPTY", "ESCAPE", "EXISTS", "FETCH",
> "FROM", "GROUP", "HAVING", "IN", "INNER", "IS", "JOIN",
>
> [snip]
>
> Presumably this is happening either because multiple joins aren't allowed,
> or I'm doing them the wrong way for this case. I suspect it's the latter,
> because the parser claims to have been expecting JOIN.
>
> I've double-checked the field names just to be sure.
> BinaryResourceReference#locales is a 1:M to
> BinaryResourceReferenceLocales, and BinaryResourceReferenceLocales#content
> is a 1:1 to BinaryResourceContent.
>
> Any thoughts or suggestions?
>
> Nick
>
>
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