Spring boot and Hibernate: print/log DDL

Question

After I've added one or more classes with database mappings (JPA/hibernate), I would like Hibernate to print out the necessary schema updates so I can execute them on the database (through FlyWay for example). I do not want the updates to be executed automatically.

The only property that seems to give some control over this is the following

org.hibernate.tool.hbm2ddl=validate|update|create|create-drop|none

I don't want to update/change anything automatically. I want to set this to validate or none. When I do this, I don't get to see the generated schema.

I classical spring application, I used to use the hibernate SchemaExport class to print the DDL.

SchemaExport schemaExport = new SchemaExport(cfg);
schemaExport.execute(true, false, false, false);

Is there anything similar I can use in Spring Boot?

Answer 1

This is what I do...

First I make my entity changes, then I set these to:

spring.jpa.show-sql=true
spring.jpa.hibernate.ddl-auto=update

Then

1. re-run my app and let hibernate make the changes to the database.
2. Go into the logs and copy the sql that hibernate used to update the db
3. Paste that sql into a new Flyway script
4. Shudown Boot App
5. Drop the local database
6. change ddl-auto back to validate
7. Restart Boot App
8. Test to make sure that Flyway made the correct updates. Hibernate and Flyway will now be in sync.