An EJB query is a string that contains the following elements:
- a SELECT clause that specifies the
enterprise beans or values to return;
- a FROM clause that names the bean collections;
- an optional WHERE clause that contains
search predicates over the collections;
- an optional GROUP BY and HAVING clause (see Aggregation
functions);
- an optional ORDER BY clause that
specifies the ordering of the result collection.
The SELECT clause is optional in order to maintain compatibility with
WebSphere Application Server Version 4.
Collections of entity beans are identified in EJB queries through the use
of their abstract schema name in the query FROM clause.
The elements of EJB query language are discussed in more detail in the
following related topics.