Exposing the schema-generation.scripts properties in the application.properties

[agoncal]

Description

This follows a discussion on Zulip[1].

To generate the DDL for JPA and/or Panache entities, I can use the schema-generation.scripts properties in the persistence.xml file as follow:

<property name="javax.persistence.schema-generation.scripts.action" value="drop-and-create"/>
<property name="javax.persistence.schema-generation.scripts.create-target" value="create.ddl"/
<property name="javax.persistence.schema-generation.scripts.drop-target" value="drop.ddl"/>

This works well, but I am trying to avoid using the persistence.xml and only use the application.properties instead. I couldn't find these properties in the Quarkus documentation, so I tried several formats but none work:

javax.persistence.schema-generation.scripts.action=drop-and-create
quarkus.javax.persistence.schema-generation.scripts.action=drop-and-create
quarkus.hibernate-orm.schema-generation.scripts.action=drop-and-create

It looks like these properties are not exposed. It would be very nice to have them so we can get the DDL files without having the persistence.xml.

[1] https://quarkusio.zulipchat.com/#narrow/stream/187030-users/topic/Any.20way.20to.20have.20a.20scripts.2Ecreate-target.20property.20.3F

[Sanne]

something different than the existing quarkus.hibernate-orm.database.generation ?

• https://quarkus.io/guides/hibernate-orm#quarkus-hibernate-orm_quarkus.hibernate-orm.database.generation

[agoncal]

The quarkus.hibernate-orm.database.generation is equivalent to the standard JPA javax.persistence.schema-generation.database.action property. It has an impact on the schema generated in the database (none, create, drop-and-create, drop).

The javax.persistence.schema-generation.scripts.action property (came later, I think in JPA 2.1) is about the schema definition. This property generates the DDL scripts, but does not generate the schema itself.

In fact, in JPA, you can have both properties to generate the database schema as well as the DDL script.

https://thorben-janssen.com/standardized-schema-generation-data-loading-jpa-2-1/

[Sanne]

Right, so you want it to also expose configuration options to generate the create.sql and drop.sql ? Wondering, should we maybe generate these always by default when running in dev mode?

…

On Tue, 2 Feb 2021, 20:06 Antonio Goncalves, ***@***.***> wrote: The quarkus.hibernate-orm.database.generation is *equivalent* to the standard JPA javax.persistence.schema-generation.database.action property. It has an impact on the schema generated in the database (none, create, drop-and-create, drop). The javax.persistence.schema-generation.scripts.action property (came later, I think in JPA 2.1) is about the schema definition. This property generates the DDL scripts, but does not generate the schema itself. In fact, in JPA, you can have both properties to generate the database schema as well as the DDL script. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#14771 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAAKMTOO4YZJUANR5FCY5VDS5BLMHANCNFSM4W62XX7A> .

[agoncal]

As you know, there are several strategies when mapping objects to a DB. Existing DB, starting from scratch, entities first, DB first.... So I'm not sure generating the DDL out of the entities should be the default in dev mode. Would that mean that these values would be the default ?

javax.persistence.schema-generation.scripts.action=drop-and-create
javax.persistence.schema-generation.scripts.create-target=create.sql
javax.persistence.schema-generation.scripts.drop-target="drop.sql

Because in JPA, the default is none:

javax.persistence.schema-generation.scripts.action=none
javax.persistence.schema-generation.database.action=none

So, TBH, I prefer the good old JPA way (no DB schema generation, no DDL generation, and you have to change the values if needed). So, if you want to be consistent with the existing Quarkus properties, maybe something like:

quarkus.hibernate-orm.database.generation=none | create | drop-and-create | drop
quarkus.hibernate-orm.scripts.generation=none | create | drop-and-create | drop
quarkus.hibernate-orm.scripts.generation.create-target=create.sql | <my create file>.sql
quarkus.hibernate-orm.scripts.generation.drop-target=drop.sql | <my drop file>.sql 

Today, to get my DDL I need a persistence.xml (which is sad ;o). And to ease the DDL generation without starting Quarkus, I use this trick, using the JPA API:

public class GenerateDDL {

  public static void main(String[] args) {
    Persistence.generateSchema("<name of the persistence unit>", null);
    System.exit(0);
  }
}

[TomasHofman]

I'm going to take a look at this.