“Unable to locate persister” (Unknown entity type in Hibernate 7) means Hibernate has no mapping for the class it received. See each cause reproduced on Hibernate 7.4 and Spring Boot 4.1, from javax imports and missing registration to DTOs, proxies and entity scanning, with a tested fix for each.
UnexpectedTypeException (HV000030) means a Bean Validation constraint sits on a type it cannot check, such as @NotBlank on an Integer. See every cause with the real message, a type-to-constraint grid, and the fix for numbers, dates, lists, Optional and your own types.
Hibernate throws GenericJDBCException: could not prepare statement when the driver rejects the SQL and gives no SQLState to classify it. See the real messages from SQLite, H2 and HSQLDB on Hibernate 7.4, how to read the root SQLException, and the fix for each cause.
Hibernate 4.3 to 5.2 throw QueryException: Cannot mix named and positional parameters when a stored procedure call registers parameters by name and by position. See the message in each version, what Hibernate 7.4 does with mixed HQL and native queries, and the fix.
HSQLDB throws “data exception: invalid character value for cast” when text reaches a number column. See the four real causes in Hibernate 7.4 and the fix for each.
Hibernate 3.6 to 4.1 stop at startup with NotYetImplementedException when a named native query has no resultClass or resultSetMapping. See the real error, the @ColumnResult workaround and how Hibernate 7 returns scalar values.
Spring throws “Bean property ‘configurationClass’ is not writable” when XML written for Hibernate 3 sets configurationClass on a newer LocalSessionFactoryBean. See the real error on Spring 7, the XML fix, and the Spring Boot 4 setup that needs no SessionFactory bean.
NoClassDefFoundError: Lorg/hibernate/cache/CacheProvider means a Hibernate 3 class (Spring’s orm.hibernate3 factory bean or an old Ehcache provider) runs with Hibernate 4 or newer. Here is the fix for old projects and the Hibernate 7 JCache setup.
NoClassDefFoundError: org/hibernate/engine/SessionFactoryImplementor means a class built for Hibernate 3, usually Spring’s orm.hibernate3 transaction manager, runs with Hibernate 4 or newer. Find the jar, switch to the matching Spring package or align the Hibernate modules, and unwrap the SPI interface on Hibernate 7.
Hibernate throws “No row with the given identifier exists” when a proxy or an eager load asks for an id that has no row. See the real Hibernate 7.4 exceptions for getReference(), lazy and eager associations and concurrent deletes, and fix them with find(), orphan cleanup, a foreign key constraint or @NotFound.
Hibernate stops at startup with “Errors in named queries” when a JPQL named query uses a table name, a column name, SQL syntax or a broken parameter. See how to read NamedQueryValidationException in Hibernate 7 and fix each cause.
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