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The NamingStrategy was already being marked as deprecated in Hibernate 4.2/4.3 (HHH-7079). Starting with Hibernate 5, now it will shipped with two replacements(?) interfaces ImplictNamingStrategy and PhysicalNamingStrategy (HHH-7078) and have finally ditched support for the old NamingStrategy. That's why Spring's upcoming Hibernate5 supported has even removed the configurer namingStrategy() and favor of implicitNamingStrategy() and physicalNamingStrategy(). So far, so good.
Although it is mentioned in some documents (i.e. in the incomplete working-5.0-migration-guide.md) and in (generated) release notes for the upcoming Hibernate 5 (as of today), I've found no concrete example how to use these actually.
Perhaps I've missed something, but neither the JavaDoc nor the issues shows any evidence of the idea both strategy types. Furthermore I've already one strategy based on NamingStrategy: a custom OracleNamingStrategy which is based on the well-known one.
While I'm interested in a proper solution in code (obviously), the actual issue is getting a working migration document and/or the conceptual idea of the restructured naming strategy.
Also related:
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3. Implicit Naming Strategy. Hibernate uses a logical name to map an entity or attribute name to a table or column name. This name can be customized in two ways: it can be derived automatically by using an ImplicitNamingStrategy or it can be defined explicitly by using annotations.
Hibernate 4 Naming Strategy ejb. naming_strategy. This strategy uses EJB3NamingStrategy , ImprovedNamingStrategy, DefaultComponentSafeNamingStrategy and DefaultNamingStrategy to map the names. EJB3NamingStrategy is the default naming strategy used and it provides camelcase field and table names.
By default, Hibernate then uses the Java class's name and the names of each of its attributes as their logical names. Hibernate's CamelCaseToUnderscoresNamingStrategy physical naming strategy replaces all dots and camel casing with underscores and changes the logical class name to lower case.
ImprovedNamingStrategy , which will convert the mixed case names to the embedded underscores name .
Put below key value pair in your hibernate configuration file
hibernate.implicit_naming_strategy=org.hibernate.boot.model.naming.ImplicitNamingStrategyLegacyHbmImpl
hibernate.physical_naming_strategy=org.hibernate.boot.model.naming.PhysicalNamingStrategyStandardImpl
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If you are providing @Table and @Column annotation in your entity classes with names provided with an underscore i.e. user_id i.e. @Column(name="user_id"), it will take the column name as user_id; if you give it as userid then it will change to user_id if you use no strategy or implicit strategy (specifically spring.jpa.hibernate.naming.implicit-strategy=org.hibernate.boot.model.naming.ImplicitNamingStrategyLegacyHbmImpl). So, if you want a strategy where the entity attribute name changes to one with underscore and lowercase letters i.e. something from userId to user_id, you should use implicit or no strategy (which actually uses implicit strategy).
If you don't want your naming strategy to add an underscore to the column name or class name, then the strategy that you need to use would look like:
spring.jpa.hibernate.naming.physical-strategy=org.hibernate.boot.model.naming.PhysicalNamingStrategyStandardImpl. The things that you provide in annotations @Table and @Column’s name attribute would remain as it is.
If you don't want to provide annotations and want to manually handle the table name and column names, you should extend the class org.hibernate.boot.model.naming.PhysicalNamingStrategyStandardImpl and override the required methods. If you still use annotations for some of the cases here, remember the overridden methods will apply on the names written in those annotations.
spring.jpa.hibernate.naming.physical-strategy=example.CustomStrategy
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