Document need to exactly match Hibernate's property format when configuring spring.jpa.properties.hibernate.* properties

[TheElk205]

I just figured that the yaml parser is not working as intended. I have this part in my application.yaml

spring:
  profiles: development
  jpa:
    show_sql: true
    database: default
    generate-ddl: false
    properties:
      hibernate:
        order_inserts: true
        generate_statistics: true
        ddl_auto: validate
        jdbc:
          batch_size: 50
          lob:
            non_contextual_creation: true

If I start my applciation now, everything is fine, sql statements are printed and batching is working.

If I now change show_sql to showSql everything still works as expected. (double checked it by setting it to false as well, to be sure that it does not get overwritten)

BUT
If I change batch_size to batchSize, sql statements are not batched any more.

I am inserting 51 values at a time here.

[wilkinsona]

Thanks for the report.

Spring Boot does not know anything about the properties beneath spring.jpa.properties.hibernate. It simply passes them through to Hibernate (with the spring.jpa.properties prefix stripped). This means that the casing of the property hibernate.* portion of the property must match what Hibernate expects.

I'm not sure that there's anything we can do about this at runtime. We can, at least, improve the documentation and describe the need to match Hibernate's expected case in the section on configuring JPA properties.