bean is persistent object and represents an object view of data stored in
Entity beans can
be of two types:
a) CMP (Entity
Bean with Container Managed Persistence)
BMP (Entity Bean with Bean Managed Persistence)
CMP, we do not need to write any SQL related code for adding a new record,
editing a record or deleting a record, or querying a table.
The EJB server itself automatically manages the creation of the table and
appropriate SQL statements.
if we want to have complex joining of data from number of tables and then
provide persistence, we will have to write our own SQL.
Hence, the need for Bean managed Persistence.
Driven Bans do not have any interface. They
are just a Java class.