Generate er diagram from Hibernate entity - java

I would like to generate ER diagram from Hibernate entities or Hibernate mapping. I have selected visual paradigm tool which provides this feature. I would like to know your feedback about visual paradigm or some other tools if you know which supports the above feature.

If you are using IntelliJ Idea (Ultimate) you can use Persistence Tool Window. In order to use this feature, you have to add Java EE Persistence Framework Support to your project or module. ( Note: To do that, go to Project Tool Window: right-click a module folder and select Add Framework Support.)
For the tool window to be available, there must be a JPA- or Hibernate-enabled module in your project, i.e. a module with a JPA or Hibernate facet.
To open the tool window, do one of the following:
Select View > Tool Windows > Persistence
If the tool window bars are
currently shown, click the Persistence button (normally located at the lower-left part of the workspace).
After that, you can generate persistence mapping. Then Right-click on the generated persistence unit and select “ER Diagram”.
References:
https://www.jetbrains.com/help/idea/persistence-tool-window.html
https://nixmash.com/post/using-intellij-persistence-view-and-er-diagram-mapping-tools

Single version of truth
Please do not use the entitys to modify the structure of the database:
if you add a non-null non-default column to a entity the database can not be changed if there are rows in that table because the initial value of that column can not be calculated.
If you add a fk to a table some values might have illegal references.
You do not like to have this problems in deployment.
Use the tools of db managers instead please and calculate the entitys from the db.

Related

Can't generate entities from database using JPA tools

I'm using JPA Tools to generate the entity classes from an existing database following this tutorial:
http://o7planning.org/web/fe/default/en/document/7758/using-hibernate-tools-generate-entity-classes-from-tables
I setup the connection, but when I try to right-click on the project name > JPA Tools > Generate Entities from Tables, I select the connection and the schema, but no table is shown to select
but of course I have a few tables in the database with the same name. This is a picture from Sequel Pro:
Dali, the Eclipse plug-in that supplies the entity generation wizard you are using, relies on another Eclipse plug-in, DTP, to provide the database metadata necessary to perform the entity generation. As a result, this problem could be caused by either plug-in.
A simple way to (possibly) isolate the problem is to use DTP's Data Source Explorer view to see what DTP is returning in the way of metadata. Use this view to connect to your database. (You will be using the same connection profile you created in the Dali Entity Generation wizard.) Once you are connected you should be able to expand the tree to see your tables. If there are no tables, the problem is with the DTP adapter used to retrieve metadata from your database and this is a problem with DTP; if there are tables in the tree, the problem is with Dali.
Also, you should look at the Eclipse log (./.metadata/.log) to see if any sort of exception occurs when you are using the Dali wizard.

Tool to generate a ERD (entity-relation diagram) based on JPA annotations

I'm writing a java code using ormlite. I was wondering if it's possible to generate an ERD from the JPA annotations in my code. Basically, I need the reverse of this: How can I transform Entity-Based diagram to a JPA java code
IntelliJ IDEA (Ultimate) provides JPA to ER-Diagram generator.
In the Persistence tool window, select appropriate node. Then use context menu to select "ER Diagram".
Note that JPA facet must be linked to module and UML plugin should be active.

How to generate model from database

I have an existing database. I need to generate the model classes in Java from it. Are there any tool/library that will allow me to do this. It will be of great help if it can emulate the entity relationships in the database into the model classes as well.
It is acceptable if the tool/library works with only one database vendor. I will create a database there and then generate the model.
Thanks in advance.
EDIT : I will probably use Hibernate as the ORM framework if I manage to generate the model.
The Hibernate Tools project (available as an Eclipse plug-in, as well as an Ant task) allows for "reverse-engineering" of database schemas into appropriate entity classes.
This project is also available in the JBoss Tools project.
The facility allows for reverse-engineering of the database metadata into a Hibernate configuration file. All artifacts (including the .java files) are generated from this config file.
You can control the nature of the reverse engineering process to suit your database structure. In other words, you can specify the schemas that you wish to have the tool reverse-engineer. You could also override the JDBC type mapping, apart from limiting the reverse-engineering process to a selected set of tables.
Obligatory link:
Screencast on Reverse engineering and code generation
Telosys does exactly this job
Let's have a look : http://www.telosys.org/
Minuteproject 4 JPA2 (http://minuteproject.wikispaces.com/JPA2) track does this task.
Minuteproject can be run from console or command line.
You can have a quick result by generating from the console where generate a maven project containing the JPA2 mapping classes in java or groovy.
If you use the command line then you need to fill an xml file that can contain additional customisation of your generated code such as packaging, enum, aliasing etc...
You can also try other track built on top JPA2 such as DAO with spring or EJB; REST; front end with Primefaces or Openxava; etc...
Hibernate has an Eclipse plugin Hibernate Tools http://www.hibernate.org/subprojects/tools.html that has reverse engineering capabilities.
See: http://docs.jboss.org/tools/3.2.0.GA/en/hibernatetools/html/plugins.html#refeng_codegen for more details on how to run and customize the reverse engineering process.

maven / eclipse JPA project and Entity generation?

Im a bit confused about this :
I've setuped a simple maven-archetype-webapp
So far i've been creating entities from a plain POJO, adding annotations as needed
But lately i think that there could be ways to ease this entity creations, so i googled
And found out about eclipse that could help me generate the JPA entities ..
I tried right clicking on my package that contains the entities, and new -> JPA -> Entity, only to find out that i can only make use of this in a JPA project.
In one hand, i have a maven project (which is not a JPA project created by eclipse), and in the other hand, i'd like to give eclipse JPA a try.
And one more thing, i have something in mind that we could design with a GUI tool, creating entities, defining the relations, defining configurations like the id generation sequence, multiple unique columns, compound key, etc and have the JPA entities generated for you.
Does this kind of tool exist ? Perhaps as an eclipse plugin or something else ?
JPA tooling can be added to an existing Eclipse project in a couple of ways, depending on the type of project you are starting with. If you have a Java project, you can right-click on it and use the "Configure" -> "Convert to JPA project..." menu item to add JPA project capabilities to an existing Java project. If you have a Web project or other WTP based project (known as "faceted" projects), you can simply add the JPA facet to the project in the project properties on the "Facets" node. If you are starting from scratch you can create a JPA project, which is basically just a Java project with JPA tooling added in.
I'm not sure if you are using m2e, but this is the Eclipse Maven integration tooling. There are some known issues using Maven with the JPA tooling in Eclipse, but there are workarounds that may work for you.
As for graphical diagramming tools for developing entities, this is coming to the Eclipse Dali Java Persistence Tools project for the next release - 3.0 (Indigo). You can try this functionality out now by downloading the JPA Diagram Editor. Check out the youtube video (search JPA Diagram Editor) for a quick demo of the functionality.
Sorry for the lack of links, but I can only post 1 per reply as a new user.

Hibernate Tools - DAO generation

I am using the eclipse hibernate tools plug-in to reverse engineer my database.
I spent my whole day looking for how to force the DAO generator to use HQL/Criteria with the session factory, transaction, etc.
Right now, if I have the table TABLE in my database, I obtain the DAO class TableHome. This class uses the persistence EntityManager.
I found tutorials using an older version of hibernate tools generating TableDAO instead, and this is what I exactly need.
Thank you very much.
Whether you're using Eclipse or not is unclear but if you are, maybe check if the Console Configuration used by the Code Generation module is not configured for JPA:
alt text http://docs.jboss.org/tools/2.1.0.Beta1/hibernatetools/html/images/plugins/plugins_2.png
See also
Section 3.4. Creating a Hibernate Console Configuration
Section 3.5. Reverse Engineering and Code Generation
Use Salto-DB Eclipse plugin. It comes with all the stuff.

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