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Although the CMP field definition in the deployment descriptor is specified by the EJB

specification, there is not a standard way to map entity beans to SQL tables and CMP

fields to SQL columns. (I hope this is addressed in the next version of the EJB

Specification.)

The mapping is left up to the discretion of the EJB container implementation. This will

likely change in a future release of EJB. Since the implementation of the reference

J2EE application server does not allow easy mapping from entity beans to SQL tables,

the examples use the mappings defined by using the

deploytool

.

You will not have to perform mappings. The mappings are provided by the included Ant

build scripts.

Defining the primary key field in the deployment

descriptor

Every entity bean must have a primary key. The

UserBean

 s primary key is the e mail

CMP field. Thus, primary key field and its type must be specified in the deployment

descriptor just like any entity bean as follows:

java.lang.String

email

Deployment descriptor

The rest of the deployment descriptor is what you would expect. Notice that the

deployment descriptor uses

2.x

to denote the

version of CMP desired. This was added to accommodate EJB containers that support

both CMP 1.0 and CMP 2.0 style container managed persistence. The complete

deployment descriptor is as follows:

Listing 1: Deployment descriptor for UserBean

Introducing EJB CMP/CMR, Part 1 of 2

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