Spring Boot 3 Data JPA - Wrong datatype mappings in native queries

I've migrated an app from Spring Boot 2.x to 3.

With Spring Boot 3 JPA's data type mapping is behaving differently. I'm using native queries in some parts that return lists of objects. The Java types of these objects have now changed.
This is with an Oracle DB.

for example:

@Query(value = "SELECT all_tab.column_name, all_tab.data_type, all_tab.DATA_LENGTH, all_tab.DATA_PRECISION, all_tab.DATA_SCALE"
				+ " FROM  all_tab_columns all_tab"
				+ " WHERE all_tab.column_name = :name", nativeQuery = true)
List<Object> findColumnDefinition(String name);

What I'm observing now, is that the mapping from DB types to Java types has changed:

• NUMBER(1,0) maps to Boolean instead of BigDecimal

• NUMBER maps to Float instead of BigDecimal

Oracle JDBC driver doc state, that all NUMBER types map to BigDecimal.

Hibernate 6's docs state this:

> By default, Boolean attributes map to BOOLEAN columns, at least when the database has a dedicated BOOLEAN type. On databases which don’t, Hibernate uses whatever else is available: BIT, TINYINT, or SMALLINT. ...

> By default, Hibernate maps values of BigDecimal to the NUMERIC JDBC type.

So what am I missing? Any ideas what causes the change in type mappings or how I can get back the Spring Boot 2 behavior?

Edit:

I can rule out jdbc. I've made the same sqls with plain jdbc and the datatypes are mapped correctly (NUMBER as BigDecimal)...

That would leave hibernate 6 as the cause?

Your same bug has been spotted here: https://hibernate.atlassian.net/browse/HHH-16650

You need to update your hibernate version (6.2.4.Final or newer)

I have a similar issue with Integer being interpreted as tinyInt. The solution was to replace <columnName> with "CAST(<columnName> as INTEGER)". It's not perfect, but works. Looking for a cleaner solution though.