Eclipse Authors: Pat Romanski, Elizabeth White, Liz McMillan, David H Deans, JP Morgenthal

Related Topics: Java IoT, Eclipse

Java IoT: Article

Managing Persistent Entities with the JPA Persistence Entity Editor

Part 4 - The Entity Editor provides a centralized view of all entity relationships

Oracle Enterprise Pack for Eclipse allows you to view, create, and manage JPA entity relationships. The Entity Editor provides a centralized view of all entity relationships, allows you to modify entity properties, and allows you to navigate between the object model, mapping associations, and database schema layers.

The tasks you will complete in this step are:

View an Entity Relationship Diagram, Using the Entity Editor
As described previously, the Entity Editor displays relationship diagrams for entities defined in the project.

  1. In the Project Explorer view, expand oepe-jpa-tutorial > JPA >Show in Entity Editor. Oracle Enterprise Pack for Eclipse provides a list of entities under the Entities branch based on the entities defined in the Persistence configurations file.

The JPA Persistence Entity Editor displays all entity relationships defined in the Web application. Each box displays a specific entity, its properties, and an icon denoting the nature of the relationship.

  1. The JPA Persistence Entity Editor displays and selects property types for an entity by using tool tip popups. You can work with entity relationship diagrams by selecting operations such as Zoom In, Zoom Out, Export to Image, and Print. To view a tool tip, hover your cursor over the respective entity. To view and edit the details, use the JPA Details View.

The JPA Persistence Entity Editor also allows you to filter relationships between entities. This feature helps you simplify your view of the diagram when it is large and complex.

  1. Click Filters and select the options Many to One and One to Many to filter which entity relationships are noted in the diagram.

  1. Reset both filters.

View and Edit JPA Persistent Entities, Using the Entity Editor
Using the JPA Details View, you can easily edit entity properties.

  1. Select the Contact entity in the JPA Entity Editor.
  2. Click the Properties tab to view the JPA Details view. The JPA Details View displays the properties for the Contact entity.

  1. With the JPA Details view, you can edit the associated Java Bean class, strategy for persistence, and the database access information for the selected entity. To edit, either enter text in the text box or click on the dropdown lists for the schema binding, Primary Key Generation, Sequence Generators, Queries, etc.
  2. In the JPA Persistence Entity Editor, select the phone property of the Contact entity. The JPA Details view displays properties of the phone property. Observe the properties.
  3. Use the JPA Details view to modify the Length of phone property. For example:
    • Set Nullable to false
    • Update the Length value from 20 to 25
    • Press CTRL+S to save the changes.

  1. Within the JPA Entity Editor, right-click the entity Contact to view its source code or see the associated configuration in persistence.xml.

Manage JPA Entity Mappings
The following describes how the annotations are translated into what the JPA Details view displays. When the JPA Details view displays an underlined label, you can click the label to view the corresponding Java source code or item in the Data Source Explorer.

  1. In the JPA Entity Editor, review the many-to-one association between OrderData and Customer. Select the customer property OrderData entity to view its properties in the JPA Details view.

  1. Within the JPA Details view, examine the Join Columns. Select the association and click Edit to edit the mapping association.
    Click Cancel.
  1. Next, locate the one-to-many association between OrderData and Lineitems.
    Click on the lineitems property in the OrderData entity and view Target Entity and Mapped By properties in the JPA Details View.
  2. Clicking Target Entity in the JPA Details View will take you to the class for the related entity type Lineitem.
  3. Close the LineItem.java file.
  4. Clicking Mapped By under the Join Properties will allow you to change the field by which the many-to-one association of OrderData to Lineitem is mapped. Do not make any changes at this time.

  1. Close the LineItem.java file.

In Part 5 I will explore persistence settings.

More Stories By Pieter Humphrey

Pieter Humphrey has been at Oracle (by way of BEA Systems) for 7+ years, working in development, marketing, sales, and developer relations to advance Java technology in the enterprise. He ran the dev2dev community at BEA and continues to with work with Oracle OTN and Eclipse Foundation communities. His current role is focused on application development tools like Oracle Enterprise Eclipse Pack, Oracle Workshop for WebLogic, JDeveloper, TopLink and the ADF framework, and is a frequent speaker at industry events and workshops.

Comments (0)

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.

IoT & Smart Cities Stories
Bill Schmarzo, Tech Chair of "Big Data | Analytics" of upcoming CloudEXPO | DXWorldEXPO New York (November 12-13, 2018, New York City) today announced the outline and schedule of the track. "The track has been designed in experience/degree order," said Schmarzo. "So, that folks who attend the entire track can leave the conference with some of the skills necessary to get their work done when they get back to their offices. It actually ties back to some work that I'm doing at the University of San...
In his general session at 19th Cloud Expo, Manish Dixit, VP of Product and Engineering at Dice, discussed how Dice leverages data insights and tools to help both tech professionals and recruiters better understand how skills relate to each other and which skills are in high demand using interactive visualizations and salary indicator tools to maximize earning potential. Manish Dixit is VP of Product and Engineering at Dice. As the leader of the Product, Engineering and Data Sciences team at D...
When talking IoT we often focus on the devices, the sensors, the hardware itself. The new smart appliances, the new smart or self-driving cars (which are amalgamations of many ‘things'). When we are looking at the world of IoT, we should take a step back, look at the big picture. What value are these devices providing. IoT is not about the devices, its about the data consumed and generated. The devices are tools, mechanisms, conduits. This paper discusses the considerations when dealing with the...
Bill Schmarzo, author of "Big Data: Understanding How Data Powers Big Business" and "Big Data MBA: Driving Business Strategies with Data Science," is responsible for setting the strategy and defining the Big Data service offerings and capabilities for EMC Global Services Big Data Practice. As the CTO for the Big Data Practice, he is responsible for working with organizations to help them identify where and how to start their big data journeys. He's written several white papers, is an avid blogge...
Dynatrace is an application performance management software company with products for the information technology departments and digital business owners of medium and large businesses. Building the Future of Monitoring with Artificial Intelligence. Today we can collect lots and lots of performance data. We build beautiful dashboards and even have fancy query languages to access and transform the data. Still performance data is a secret language only a couple of people understand. The more busine...
If a machine can invent, does this mean the end of the patent system as we know it? The patent system, both in the US and Europe, allows companies to protect their inventions and helps foster innovation. However, Artificial Intelligence (AI) could be set to disrupt the patent system as we know it. This talk will examine how AI may change the patent landscape in the years to come. Furthermore, ways in which companies can best protect their AI related inventions will be examined from both a US and...
Enterprises have taken advantage of IoT to achieve important revenue and cost advantages. What is less apparent is how incumbent enterprises operating at scale have, following success with IoT, built analytic, operations management and software development capabilities - ranging from autonomous vehicles to manageable robotics installations. They have embraced these capabilities as if they were Silicon Valley startups.
Chris Matthieu is the President & CEO of Computes, inc. He brings 30 years of experience in development and launches of disruptive technologies to create new market opportunities as well as enhance enterprise product portfolios with emerging technologies. His most recent venture was Octoblu, a cross-protocol Internet of Things (IoT) mesh network platform, acquired by Citrix. Prior to co-founding Octoblu, Chris was founder of Nodester, an open-source Node.JS PaaS which was acquired by AppFog and ...
The deluge of IoT sensor data collected from connected devices and the powerful AI required to make that data actionable are giving rise to a hybrid ecosystem in which cloud, on-prem and edge processes become interweaved. Attendees will learn how emerging composable infrastructure solutions deliver the adaptive architecture needed to manage this new data reality. Machine learning algorithms can better anticipate data storms and automate resources to support surges, including fully scalable GPU-c...
Cloud-enabled transformation has evolved from cost saving measure to business innovation strategy -- one that combines the cloud with cognitive capabilities to drive market disruption. Learn how you can achieve the insight and agility you need to gain a competitive advantage. Industry-acclaimed CTO and cloud expert, Shankar Kalyana presents. Only the most exceptional IBMers are appointed with the rare distinction of IBM Fellow, the highest technical honor in the company. Shankar has also receive...