This code is causing the following exception on the startup I’m using H2 in-memory database. Student entity: Passport entity: Question 1: What is the reason for org.hibernate.DuplicateMappingException? Question 2: Why does adding the following annotation to passportId in the Student entity resolve the i…
Tag: hibernate-mapping
Hibernate: mapping with a map and getting argument type mismatch
I’ve got this class DepartmentPerson in Java where I’ve mapped a Map in Hibernate as following: and in the class I have acceptByPeriod defined as following: Whenever I run a query on DepartmentPerson, I get the message: “java.lang.IllegalArgumentException: argument type mismatch”. This…
Non-Redundant Hibernate List-Mapping (OneToMany)
In a database there are “pastries”. A pastry has zero, one, or many allergens. Hence I’m using a list in Pastry with @OneToMany relation. Now, with this way of managing the relations, we get redundant entries, as for each pastry a new entry with the same allergen is created: Our current solu…
JPA Embeddables – Multiple per Entity, Single Table for all Entities
I’m exploring options for being able to store specific addresses (home, work etc.) for multiple entities, and having a single table that holds all addresses, probably with some kind of discriminator per record. The primary keys for all tables are UUIDs. I’m using Spring Boot 2.3.6 and JPA/Hibernat…
JPA SQL Result Mapping
my code is mapping query result to DTO using Sql Result Mapping and create list with these dtos but in my database id can be null and it gives me trouble in mapping. That’s why I don’t want to use it instead of that, is there any way to generate id’s for these dto’s not getting them fr…
“Illegal attempt to map a non collection as a @OneToMany, @ManyToMany or @CollectionOfElements”
Good morning Stackoverflow, I have the problem that it gives me the error: Failed to create sessionFactory object.org.hibernate.AnnotationException: Illegal attempt to map a non collection as a @OneToMany, @ManyToMany or @CollectionOfElements: nl.scalda.pasimo.model.employeemanagement.EducationTeam.coachGroup…
How to map an immutable collection with JPA and Hibernate
I am using JPA 2.1 and Hibernate as a JPA implementation, and I want to load a relationship as an immutable collection. Let’s take an example of an Employer parent entity that has an employees child collection. What can be done to instruct JPA to load an immutable employees collection? Answer You can us…
Hibernate: New Session without dropping the tables
I am new to Hibernate (implementing since yesterday) and i succesfully created a method, that transfers my Customer Objects to the Database. After i quit my application and start it again and create a new session (in an other method) based on my hibernate.cfg.xml file with this setting: It leads to that point…
How to specify a Primary Key on @ElementCollection
So, there is that behavior with innodb that can cause problem if some tables lack of primary key. So with Hibernate, I am looking for a key to specifies a primary key on a @ElementCollection table with a Set as the underling data structure. I found a way to have a primary key with a map, but it is kind
Hibernate mapping between PostgreSQL enum and Java enum
Background Spring 3.x, JPA 2.0, Hibernate 4.x, Postgresql 9.x. Working on a Hibernate mapped class with an enum property that I want to map to a Postgresql enum. Problem Querying with a where clause on the enum column throws an exception. Code (heavily simplified) SQL: Hibernate mapped class: Java that calls …