hibernate-annotations

I want do a one-to-many relationship between two tables using a join table. This is why I want to use a join table: Hibernate unidirectional one to many association - why is a join table better? Why is it recommended to avoid unidirectional one-to-many association on a foreign key? Finally, I want to use Hibernate annotations to perform this. I found some examples to do this using xml mapping but nothing with annotations. I believe this would be how the tables need to be created CREATE TABLE `PRODUCT` ( `PRODUCT_ID` BIGINT PRIMARY KEY AUTO_INCREMENT ); CREATE TABLE `PARTS` ( `PART_ID` BIGINT

I need to configure hibernate to avoid creating duplicate rows, (although the row exists it creates a new one, and since only one filed is set it set all the rest to NULL) Lets say I have a row as following id des index age 1 MyName 2 23 Although I just set MyName as des and it already exists in the Name table hibernate create a new row as following id des index age 1 MyName 2 23 2 MyName Null Null << new row with null values will be created rather than updating the previous one When I want to sa . So I have added the following annotation to my class but it crossed the Entity, and

I am new to hibernate. What I am trying to do is use @CollectionId to generate an identifier for my Address class. I have used Collection interface for this. However when I use @GenericGenerator and set strategy to hilo, it throws an Exception. Here's my code: @Entity @Table(name = "USER_DETAILS") public class UserDetails { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private int userId; private String userName; @ElementCollection @JoinTable(name="USER_ADDRESS", joinColumns=@JoinColumn(name="USER_ID") ) @GenericGenerator(name = "hilo-gen", strategy = "hilo") @CollectionId(columns =

In the class Parent there is a list List. When the parent is saved the children which have been added or changed shall be save / updated by hibernate. I've found many explanations on this, however, I just don't get it to work. Parent.class try A @Entity public class Parent { // id and other attributes @OneToMany(mappedBy = "parent") @org.hibernate.annotations.Cascade(org.hibernate.annotations.CascadeType.ALL) protected List<child> children; Parent.class try B @Entity public class Parent { // id and other attributes @OneToMany(mappedBy = "parent", cascade = { javax.persistence.CascadeType.ALL }

This is my annotation class and i want userId and groupId column both as primary key. I have found more questions ( Question ) about this, but didn't found relevant answer. I have less reputation, so I am not able to comment on posts, So I am putting my question here. This is my code.. import javax.persistence.Column; import javax.persistence.EmbeddedId; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.Table; import org.hibernate.annotations.NaturalId; @Entity @Table(name=