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.
Related
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.
I am having tables created by a DBA and I intend to have
entity classes for each table for further querying. Can any one suggest how to automatically create the entity classes using Eclipse?
If you use JPA for persistence, you can use "JPA tools" provided by Eclipse to generate java entity class from tables.
Here is the [tutorial][1]
[1]: http://shengwangi.blogspot.com/2014/12/how-to-create-java-classes-from-tables.html on my personal website.
You can generate classes using Hibernate Tools. There are two ways to generate these classes which is called as Reverse Engineering and Code Generation[dead link] -
You can use Hibernate Tools Eclipse Plugin.
You can write Ant Script using Hibernate tools jar.
You can try the Telosys code generator. It can help for this kind of job.
It allows to generate the Java (POJO) classes from any database
with the basic templates and you can also create your own
template (a Velocity file) to generate your DAO classes
For more information see https://www.telosys.org
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.
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.
Are there any Java code generation persistence frameworks?
Something that is "database first" rather than object model first?
I know this is probably heresy in the Java world, I'd just like to know if any frameworks like this exist.
I'm more of a .NET guy these days. So on the .NET-side tools like .NET Tiers or CSLA come to mind.
sure, hibernate and netbeans for example can reverse engineering a database. You may be want to look at:
Hibernate Tools; site in maintenance
netbeans, with recent version of netbeans you can create JPA entities from a JDBC connection
My 2 cents.
The Apache Cayenne ORM framework is able to reverse engineer a database. See here.
I developed jOOQ to exactly suit your needs - so don't worry about the heresy :-)
Check out the examples page or an article on dzone illustrating my motivations of creating such a framework. The main advantages are:
It generates source code
It stays close to SQL by providing a SQL-like DSL in Java
It supports easy access vendor-specific features, such as UDT's, stored procedures
It supports all advanced SQL features, such as UNIONs, nested SELECTs, aliasing, etc
Note that jOOQ is NOT really an OR-mapper. It focuses on the relational datamodel from your RDBMS and doesn't give you the possibility to create your custom object-oriented domain model like Hibernate or JPA do. This is precisely for the reason you mentioned yourself: Something that is "database first" rather than object model first
Checkout EclipseLink project ( plugins for eclipse) , you can generate JPA models from database tables
DB Importer is an Eclipse plug-in that generates JPA classes from a database.
Disclaimer: I am the creator of DB Importer.
Telosys Tools is a free "database first" code generator
See : https://sites.google.com/site/telosystools/
It's an Eclipse plugin, the templates are customizable if necessary
It can generate the persistance layer (JPA) but also the CRUD Screen
( tutorials are here : https://sites.google.com/site/telosystutorial/ )
Many of the Java-based persistence tools include tools to generate code based upon an existing schema. Netbeans will generate JPA (including Session bean facades, if desired). Similarly, JBoss Tools for Eclipse will generate Hibernate JavaBeans for you based upon an existing schema.
I would recommend HiberObjects. It's an Eclipse plugin that can be used to model persistent objects or reverse engineer an existing database. The way it lets you set up unit tests is truly awesome. You can also modify how for instance DAO classes are generated: just modify a Groovy script and all DAO-classes are re-generated. I have encountered a few bugs, but the guy behind it has been very responsive and released fixes in short time. A description and user ratings/comments are found at Eclipse Plugin Central.