I want to get the schema from one table from my hsqldb database. At the moment everything is generated with hibernate. Is there a fast and easy solution to get the schema out of the hsqldb?
I appreciate your answer!
I often use SchemaSpy to generate an html description of a schema including relationship graphs. It uses a JDBC driver to fetch the schema information, so this works with any DB that has one.
http://schemaspy.sourceforge.net
Try SCRIPT.
Same question here: look here too.
Related
I would like to find a reliable way to test my Maria DB schema with Jooq.
This is what I have now:
let Jooq with Gradle to extract an XML schema from the real DB (i.e. Maria instance) via org.jooq.codegen.XMLGenerator, this step will generate a maria_information_schema.xml;
use this schema to generate all the Java Classes.
To test all the classes I will write I have develop a technique:
fire a H2 embedded in ram database;
build a java InitDatabase.java class which manually set a DB schema as similar as possible with the MariaDB one;
preform all the test on the in ram DB.
This procedure works perfectly as far as I don't change something on the real DB and I forgot to do the same on the InitDatabase.java class.
My question is: is there a way to use the XML schema or the generated java classes to create an H2 Database with the same schema as the MariaDb one without writing manually all the create table statement?
Thanks
This is an open ended question with no obvious, "correct" answer. jOOQ's official take here is that you may want to re-consider using alternative RDBMS for testing what you could be doing with your target RDBMS directly, specifically using testcontainers.
You could combine this approach with jOOQ's code generation for a more streamlined development process.
In short, jOOQ's recommendation is to use:
Flyway or Liquibase for database change management
Testcontainers for code generation
Testcontainers for integration testing
Other, equivalent products are obviously also possible.
with the property spring.jpa.hibernate.ddl-auto it's possible to auto generated table from entities.
What I need is that only some specific entities should be generated to tables in database an the rest of the entities do nothing.
It this possible ?
I guess this is your question here? https://discourse.hibernate.org/t/i-would-really-like-to-know-more-about-the-update/5455
Like I wrote there already, you shouldn't use hbm2ddl for anything other than development purposes. Use a proper schema management tool like Liquibase or Flyway.
As #pcsutar already commented, impl said SchemaFilterProvider
I'm seeking for same functionality in Java that present in PHP's Doctrine ORM.
I can describe an entity and the doctrine:migrations:diff console command will make me a fine migration which will generate SQL for updating the database schema. then I can update current database schema with new fields/tables etc running doctrine:migrations:migrate
But what's the same way to do it in Java? I've tried to do it with Flyway, but had no luck because it can't just get the entity and generate diff: https://github.com/flyway/flyway/issues/648#issuecomment-64208848
So, I just tried to do it with liquibase, but don't understand how to do it.
I've tried to ask this question in #java room on irc.freenode.net, but the closest answer was "let hibernate create the schema and have liquibase extract it" (thank you, k5_)
but… how?
many sources say that I must use somewhat "hibernate.hbm2ddl.auto"… but how? what is it?
I'm surprised that there's no examples "for dummies" over internet for this important functionality
I think that it is a terrible way to write all migrations by hands and I just don't believe that there are no solutions exist
please, help me
thank you in advance!
UPD
In my particular case I'm using Hibernate, I have basic entities defined (with OneToMany, ManyToOne mappings)
I want to start on clean database and updating its schema with migrations.
So my goal is to generate this migrations automatically from entities descriptions compared to current database schema state.
UPD 2
The second closest answer is (thanks once again, k5_): "configure hibernate to create a schema when it doesnt exist (just add the configuration option you posted to the persistence.xml). Start the server it will create a schema in a database. Use the liquibase to extract the schema. Or use it to create a diff over two databases."
I want to test my program with an inmemory hsqldb. To create the table I use hibernate.hbm2ddl.auto=create
But I get an exception because the schemas, defined in the entity classes by annotations, are not created before the tables are created. Now I am searching for an opportunity to create the schemas before hibernate.hbm2ddl.auto runs. To remove the schemas is not an opportunity for me, because I need them for my program.
My problem is pretty much the same like this. The different is I do not use spring, so the solution does not work for me.
Assuming that you're using H2 database, you may provide init command to run with jdbc connection url. For example:
your.jdbc.url=jdbc:h2:mem:;DB_CLOSE_DELAY=-1;INIT=create schema IF NOT EXISTS your_schema
Unfortunately, the issue on hibernate jira is still unresolved https://hibernate.atlassian.net/browse/HHH-5665
Since Hibernate 5 there is a cleaner and more db-independent way, which also works with hsqldb. Add this configuration property:
hibernate.hbm2dll.create_namespaces=true
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