OPENJPA-20: Clarify return of embedded instances as query result

git-svn-id: https://svn.apache.org/repos/asf/openjpa/trunk@680421 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Pinaki Poddar 2008-07-28 17:52:06 +00:00
parent 72b5b4def8
commit 5fc632784f
1 changed files with 7 additions and 1 deletions

View File

@ -65,7 +65,13 @@ an entity by its persistent identity (covered later in this chapter), or use a
An instance of an embeddable class, on the other hand, is only stored as part of
a separate entity. Embeddable instances have no persistent identity, and are
never returned directly from the <classname>EntityManager</classname> or from a
<classname>Query</classname>.
<classname>Query</classname> unless the query uses a projection on owning class
to the embedded instance. For example, if <classname>Address</classname> is
embedded in <classname>Company</classname>, then
a query <classname>"SELECT a FROM Address a"</classname> will never return the
embedded <classname>Address</classname> of <classname>Company</classname>;
but a projection query such as
</classname>"SELECT c.address FROM Company c"</classname> will.
</para>
<para>
Despite these differences, there are few distinctions between entity classes and