This task describes how to add a column for collision detection
using the Mapping editor.
Prerequisite tasks- Enable the J2EE and Database Capabilities. You can complete
this as follows:
- In the workbench preferences page (Windows > Preferences)
expand the folder Workbench , select Capabilites.
- Under the Capabilities list, select the check
boxes: J2EE Developer. Click OK.
- Create a version 1.3 or 1.4 enterprise application project with a target
server of WebSphere® Application
Server v6.0..
- Create a version 2.x EJB project in the enterprise application project
you just created.
- Create or import a 2.x CMP beans in the EJB project that correspond to
the enterprise application project you just created.
- Generated an enterprise bean using either top-down, bottom-up1 or meet-in-the-middle approach.
- Created a JDBC Connection.
- Set up the optimistic access intent to wsOptimisticUpdate or wsOptimisticRead.
Steps for this taskTo generate a collision detection column
for EJB 2.x CMP entity bean using the Mapping editor, complete the following:
- Open the Mapping Editor.
- In the J2EE perspective, expand the EJB project for which you
want to add the column for collision detection.
- Expand the Deployment Descriptor folder.
- Expand the Maps folder. Right-click
the database mapping and select Open With > Mapping
Editor.
- In the Overview section, under Enterprise
Beans expand the EJB project folder and select the CMP bean you
want to add a column for collision detection.
- In the Properties view, expand the Bean
to Table Strategy section, use the Column for Collision Detection list
to select a column for collision detection.
Restriction: You
need to choose a column that is not mapped to a CMP field, otherwise undefined
behavior may occur.
Post task
Before using the collision detection column,
you must complete the following:
- Create your own database trigger to support the use of the collision detection
column.