Add/remove column fields for Existing EJB

Please find the below steps to make modifications for the existing data model like adding or deleting a table column.

• Open bean class in Deployment descriptor and add/delete CMP attribute as per requirement.
• Demote ejbCreate (In outline: Right click on ejbCreate and select Enterprise Bean -> select Demote from Home Interface)from bean.java file for the respective EJB.
• Add/delete CMP attribute in ejbCreate and ejbPostCreate argument lists for the Bean.java file.
• Now promote ejbCreate to Home interface
• Modify _copyToEJB and _copyfromEJB methods to account for added/removed field
• Modify data definition:  WebSphereCommerceServerExtensionsData > ejbModule > META-INF > backends > {databaseType} > MALL_NULLID_{tableName}.tblxmi. Add/delete column from table definition.
• Modify EJB to RDB mapping:   WebSphereCommerceServerExtensionsData > ejbModule > META-INF > backends > {databaseType} > Map.mapxmi
• If adding an EJB field, map the field to the table column.
• If deleting a field, remove it from the mapping. Note: The field may already have been removed from the mapping when the deployment descriptor and data definition were saved in the previous steps.
• Deploy.  If the following error occurs, There are no enterprise beans in WebSphereCommerceServerExtensionsData, delete all auto-generated files (prefixed with the underscore), and deploy again.

Once we are done with the above steps we can Build and regenerate the access bean.

Note: A number of files are generated automatically when the EJB is first created, so it’s not always clear which code should be updated and we modify the _copy methods to ensure that all bean references are updated.  Without the above steps, the deployment descriptor sometimes may revert to the original bean definition.