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.
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 new in the hibernate world. My project task is to represent xml result from the SQL database. To do so, first step, I am trying to generate POJOs and mapping xml from my db by using hibernate tools auto generating feature. When, i am trying to generate a simple database (2/3 tables) its working fine.
But while i trying to convert my real database, which has 28 tables within different table relationships. Then i am facing the below problem. Not able to connect the database tables. Hibernate tools configuration showing this terrible message.(Foreign key name (fk_p_einheit) mapped to different tables! previous: org.hibernate.mapping.Table(public.einheit_quelle) current:org.hibernate.mapping.Table(public.spalten)
I checked google to get the solution but not get any proper solution related to eclipse IDE. Just got one BUG report from NetBeans site(https://netbeans.org/bugzilla/show_bug.cgi?id=205863).
My setup configuration is:eclipse-jee-luna-SR1-win32-x86_64, postgres (sql 9.1-901.jdbc4) and hibernate core (4.3.5.Final) with maven project and hibernate tools.
Any one please help me.
You need an object model that maps all of those 28 tables and relationships. Do you have one? If not, why are you using Hibernate?
You can ask Hibernate to generate an object model for you from the schema. Try it.
Why are you using all these unknown technologies (Hibernate, Eclipse, etc.) to do something simple?
If you're thinking in terms of tables and columns, and not objects, I'd say you'd be better off writing JDBC and straight SQL. ORM tools aren't for you.
I'm writing my first webapp on IDEA. I'm having a small problem with model classes. IDE can't resolve a names of tables, columns, attributes, ect. from a database and marks this as errors. I DO have a Data Source configured (even on IDE scope). Do anybody know how to bypass that (while having a working project of course :))?
As in title, I'm using an IntelliJ IDEA 12.1.6 version.
Please check the documentation:
In the Data Sources Mapping section, specify the data source for each Hibernate session factory. To do that, select the desired entry in the Session Factory column, double click the corresponding Data Source, and select one from the list of data sources already configured in your workspace.
I trying to use EclipseLink JPA provider with H2 DBMS in Eclipse IDE.
When I create a new JPA project and fill the data (URL="jdbc:h2:~/test",Username="user",password="") connection type : resource local (I'm using the embedded mode)
I get 2 odd things :
when I try to create Entities from table I get a blank table list
I get an error message near #Entity notation saying that "catalog User can't be resolved for entity e1" or "Schema User can't be resolved for entity e1" depending on keeping the default value for catalog or changing it upon project creation where User is the database user name
The database already contains tables using the h2 console in Firefox
What is the cause of these problems and how can I solve it and do you have any page or book that can help with persistence.xml file (other than the oracle official web site)?
EclipseLink doesn't create the database tables for you, unless you explicitely tell it to do so.
The way to do that is described in the documentation
EclipseLink can be used to automatically generate the tables and database schema for a persistence unit. This is done through the "eclipselink.ddl-generation" persistence unit property, set to either "create-tables" or "drop-and-create-tables". The tables and constraints will be generated for all of the classes defined in that persistence unit.
The trick was to set the right catalog when creating the JPA Project and then every thing worked splendidly
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.