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
Related
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 am working on a project in Java (using Spring Boot, Thymeleaf, Hibernate, JPA, MySql). Every time I create a new Model Class, I have to create a table in the database or if I make any change in the Model class I have to alter the table by myself. Is there any way to avoid this database related stuff. For example I will make Model classes and declare their relationships my Database tables will be generated automatically. In future if I make any changes to my classes they will be applied to the database automatically without loosing any data.
Previously I worked on PHP, Laravel. There all I needed to do is 1) run command php artisan make:migration create_posts_table, 2) declare columns like $table->string('title');, $table->foreign('user_id')->references('id')->on('users'); and then 3) run command php artisan migrate. That's it. No SQL scripts needed. I was wondering if Java, Spring has something like this.
Sure you can do it.
Use spring.jpa.hibernate.ddl-auto=update in your application.properties.
You can also use more advanced tools like https://www.liquibase.org/
Ideal way
spring.jpa.hibernate.ddl-auto=none
In my opinion, the ideal way is to create one SQL file which will create the schema at the startup for us.
To let Spring Boot to create it for you
spring.jpa.hibernate.ddl-auto=update
spring.jpa.hibernate.ddl-auto= # DDL mode. This is actually a shortcut for the "hibernate.hbm2ddl.auto" property. Defaults to "create-drop" when using an embedded database and no schema manager was detected. Otherwise, defaults to "none".
Other Possible values: create, create-drop, validate
More Detailed Explanation
You can do migration using Flyway, it's similar to Laravel migration.
Add the dependency and put your migration SQL files to classpath:db/migration. Flyway will automatically check the sql files version and apply any pending migrations.
https://flywaydb.org/documentation/plugins/springboot
I'm trying to include my own schema changes (such as varchar to text and create Index) just before entities get bound, just like Hibernate does the schema update. It is ideal if I can include my own custom SQLs in hibernate's schema update itself. For instance by extending an existing hibernate class and allowing application to use mine instead of built-in one.
org.hibernate.internal.SessionFactoryImpl is final.
May be by implementing my own org.hibernate.tool.schema.spi.SchemaMigrator. Anyone tried this before?
BTW, I'm using spring boot v1.4.0.M3, in case it has any specific dependencies, I don't think so.
Cheers!
Spring Boot has a JDBC initializer, it runs .sql scripts at startup.
I would recommend using Flyway, it keeps track of the version of your database and which scripts have been executed.
http://docs.spring.io/spring-boot/docs/current/reference/html/howto-database-initialization.html#howto-initialize-a-database-using-spring-jdbc
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'm using Hibernate (JPA2) hibernate.hbm2ddl.auto=update for test and hibernate.hbm2ddl.auto=validate for production.
What I want to do is, extending the generated schema with an additional table (that is not mapped to an entity) so that this table is generated for the tests and verify for production.
Is this possible, and how?
Yes, it's possible using "auxiliary database objects". I wrote a blog post on the topic because the documentation wasn't the greatest.
Edit: One other undocumented feature of Hibernate that I didn't mention in that blog: if you include a file named "import.sql" in the root of your classpath when you run a Hibernate schema export, it will also execute the statements in that file.
Write an SQL script to create the table. When you release up the environmental chain, run the SQL first to create the table in Prod. Then validate will be fine.