example.cmp.ejbql
Interface CourseHome
- All Superinterfaces:
- javax.ejb.EJBLocalHome
- public interface CourseHome
- extends javax.ejb.EJBLocalHome
Home interface for the Course bean.
The Home Interface enables you to create new entities and to obtain
references to existing ones.
The CourseHome example provides two finder methods: the standard
findByPrimaryKey and a findByHouse method. Find methods for a local
home always return the local interface or a collection of
the local interface.
All find methods except findByPrimaryKey need an EJB-QL query in
the deployement descriptor.
Method Summary |
java.util.Collection |
findByHouse(java.lang.String house)
Finds all the courses for the students living in a house. |
Course |
findByPrimaryKey(java.lang.String primaryKey)
This is an example of a finder method that returns a single entity if
successful, and throws an ObjectNotFoundException if it
was unsuccessful. |
Methods inherited from interface javax.ejb.EJBLocalHome |
remove |
findByPrimaryKey
public Course findByPrimaryKey(java.lang.String primaryKey)
throws javax.ejb.FinderException
- This is an example of a finder method that returns a single entity if
successful, and throws an
ObjectNotFoundException
if it
was unsuccessful.
Every entity EJB needs to define this finder method that looks for an
entity based on the primary key.
findByHouse
public java.util.Collection findByHouse(java.lang.String house)
throws javax.ejb.FinderException
- Finds all the courses for the students living in a house. The example
methods shows how a query can use the IN(...) expression to select
a collection of entities.
SELECT DISTINCT OBJECT(course)
FROM ejbql_student student, IN(student.courseList) course
WHERE student.house.name=?1
- Parameters:
house
- the name of the student's house.- Returns:
- the matching collection of courses.