set spring.jpa.properties.hibernate.id.new_generator_mappings=true by default

[xenoterracide]

Hibernate has a tendency to throw these warnings in Hibernate 5

[WARN ] [11:58:26] [localhost-startStop-1] orm.deprecation - HHH90000014: Found use of deprecated [org.hibernate.id.SequenceGenerator] sequence-based id generator; use org.hibernate.id.enhanced.SequenceStyleGenerator instead.  See Hibernate Domain Model Mapping Guide for details.

setting spring.jpa.properties.hibernate.id.new_generator_mappings=true will stop it and is good for new projects, and I believe fine for old projects in most cases. I believe this should be the default in the next major version of Spring Boot's autoconfig, and probably called out in upgrade documentation.

[wilkinsona]

I think this change has broken DataJpaTestIntegrationTests testEntityManagerPersistAndGetId

[mbhave]

@wilkinsona was about to fix it by adding this.entities.flush() but I guess this works too.

[wilkinsona]

That might be better, I don't know really. Feel free to change it to call flush() if you prefer.

[mbhave]

Reopening to fix the SampleDataJpaApplicationTests and SampleJpaApplicationTests

[mbhave]

Reverting the change for now till we figure out what the best way to fix the tests is.

[philwebb]

I wonder if we should add the spring.jpa.hibernate.use-new-id-generator-mappings=false property to application.properties? I have a feeling that the samples now won't run outside of the tests.

The other option is we look at somehow updating the insert.sql file to trigger the new sequence generators.

[mbhave]

you're right, I'll give updating import.sql a shot.

[snicoll]

It looks like the flyway sample is failing but the build doesn't. Could it be related to this issue?

[mbhave]

yes I believe it is. I have a fix for it on this here. I wasn't totally sure about the best way to fix the samples, so waiting for a review to merge it in.

[LaurenceMommers]

Currently the documentation still states that the property defaults to false for backwards compatibility.
This change also leads to some weird behavior where by default a sequence table is used in mysql instead of the autoIncrement feature HHH-11014

line 181 of JpaProperties.java

/**

• Use Hibernate's newer IdentifierGenerator for AUTO, TABLE and SEQUENCE. This is
• actually a shortcut for the "hibernate.id.new_generator_mappings" property.
• When not specified will default to "false" for backwards compatibility.
  */

[wilkinsona]

Thanks for spotting that, @LaurenceMommers. I've opened #11064.