Guillaume VON TOKARSKI ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=5a9c818... ) *updated* an issue Hibernate ORM ( https://hibernate.atlassian.net/browse/HHH?atlOrigin=eyJpIjoiYjNhZDkwY2Jj... ) / Bug ( https://hibernate.atlassian.net/browse/HHH-16241?atlOrigin=eyJpIjoiYjNhZD... ) HHH-16241 ( https://hibernate.atlassian.net/browse/HHH-16241?atlOrigin=eyJpIjoiYjNhZD... ) Unable to write/query attribute on type with AttributeConverter ( https://hibernate.atlassian.net/browse/HHH-16241?atlOrigin=eyJpIjoiYjNhZD... ) Change By: Guillaume VON TOKARSKI ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=5a9c818... ) The model has {{java.time.YearMonth}} attributes being mapped to integers on the DB (MariaDB) Here is how it was used: {code:java}@Convert(converter = YearMonthConverter.class) @Column(name = "month", nullable = false) private YearMonth month;{code} And here is the converter class (based on Jakarta now): {code:java}public class YearMonthConverter implements AttributeConverter<YearMonth, Integer> { @Override public Integer convertToDatabaseColumn(YearMonth attribute) { return attribute == null ? null : (attribute.getYear() * 100) + attribute.getMonth().getValue(); } @Override public YearMonth convertToEntityAttribute(Integer dbData) { return dbData == null ? null : YearMonth.of(dbData / 100, dbData % 100); } }{code} Adding a demo project to the ticket with 2 errors: * Persisting the entity gives {{PersistenceException}}: ** message: {{(conn=9) You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'year_month, id) values (202212, 1)' at line 1}} * Searching the entity with {{ =}} gives a {{PersistenceException}}: ** query: {{SELECT de FROM DemoEntity de WHERE de.yearMonth = :yearMonth}} ** message: {{Converting org.hibernate.exception.SQLGrammarException to JPA PersistenceException : JDBC exception executing SQL [select d1_0.id,d1_0.year_month from demo_table d1_0 where d1_0.year_month=?]}} * Searching the entity with {{ MAX}} gives an {{IllegalArgumentException}} : ** query: {{SELECT MAX(de.yearMonth) FROM DemoEntity de}} ** message: {{org.hibernate.QueryException: Parameter 1 of function max() has type COMPARABLE, but argument is of type java.time.YearMonth}} Let me know if there is anything else that I can provide. ( https://hibernate.atlassian.net/browse/HHH-16241#add-comment?atlOrigin=ey... ) Add Comment ( https://hibernate.atlassian.net/browse/HHH-16241#add-comment?atlOrigin=ey... ) Get Jira notifications on your phone! Download the Jira Cloud app for Android ( https://play.google.com/store/apps/details?id=com.atlassian.android.jira.... ) or iOS ( https://itunes.apple.com/app/apple-store/id1006972087?pt=696495&ct=Em... ) This message was sent by Atlassian Jira (v1001.0.0-SNAPSHOT#100217- sha1:65be9f2 )