Generally we generate tables from Hibernate JPA to Database, but however i want to generate reverse, i.e from Database to Entity (from table to pojo).
Can you please suggest solution for:
is it possible?
is it recommended(if you have near about 1000 table)?
or should I go manually by creating POJO.
(I am using Microsoft SqlServer as DB and Spring boot (STS) in back end)
Thanks in Advance!
Related
Does anyone have experience with Spring JPA + Hibernate so that the Native Query can adapt to the database we are using? (Compatible with multi database)
For example, if we connect to PostgreSQL we will use query A, if we connect to MySQL we will use query B.
Is the solution is to create 2 or more different Repositories?
or is there a more elegant solution?
First note, because Native Query PostgreSQL is different from Native Query MySQL.
Second note, I want to make software that the user will be able to choose what database they want to use, as long as it is supported by hibernate. So user just need to change the configuration file.
Thank you
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.
How can I convert a schema that I have in Sql Workbench to Java entities for Hibernate?
Is there an easy way?
I would first generate the SQL script from MySQL WorkBench, then physically create the schema in a local database instance.
You can then generate the Hibernate entities direct from the database.
Plenty of guides online for this last step. E.g. http://www.mkyong.com/hibernate/how-to-generate-code-with-hibernate-tools/
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 need a tool for converting database tables to entity java files for hibernate.
There are 20 tables (mysql) and I don't want to copy table's column name to my Java file and so on.
Any suggestions ?
Thanks.
Hibernate Tools.
Keep in mind that entity classes / mappings that Database Reverse Engineering tool will generate may not be ideal (depending on complexity of your database) and you'll have to manually update them.
Take a look at this question as well.
Eclipse DALI, Netbeans jpa-plugin and Oracle JDevelopper.
If you have sql schema, you can use https://converter.aldoraweb.com to convert it