many-to-one

JPA OneToMany and ManyToOne throw: Repeated column in mapping for entity column (should be mapped with insert=“false” update=“false”)

由 时光毁灭记忆、已成空白 提交于 2019-11-27 03:11:15
I have three classes one of the name is User and this user have other classes instances. Like this; public class User{ @OneToMany(fetch=FetchType.LAZY, cascade = CascadeType.ALL) public List<APost> aPosts; @OneToMany(fetch=FetchType.LAZY, cascade = CascadeType.ALL) public List<BPost> bPosts; } public class BPost extends Post { @ManyToOne(fetch=FetchType.LAZY) public User user; } public class APost extends Post { @ManyToOne(fetch=FetchType.LAZY) public User user; } it's working like this but generates emty tables in db. Which have to contains foreign keys. When I tried to use mappedBy and

Hibernate Many to one updating foreign key to null

由 谁说我不能喝 提交于 2019-11-27 02:59:19
问题 I am trying to get my @OneToMany and @ManyToOne relationships correct. Class 1: @Entity public class IdeaProfile { @Id @GeneratedValue private int ideaProfileId; private String name; Date dateConcieved; @OneToOne @JoinColumn(name="statusCode") private Status status; @OneToMany(fetch=FetchType.EAGER, targetEntity=Pitch.class, cascade=CascadeType.ALL) @JoinColumn(name = "ideaProfileId") private List<Pitch> pitchs; ....getters and setters.... Class2: @Entity public class Pitch { @Id

Cannot make @ManyToOne relationship nullable

由 拜拜、爱过 提交于 2019-11-26 20:14:28
问题 I have a many-to-one relationship that I want to be nullable: @ManyToOne(optional = true) @JoinColumn(name = "customer_id", nullable = true) private Customer customer; Unfortunately, JPA keeps setting the column in my database as NOT NULL. Can anyone explain this? Is there a way to make it work? Note that I use JBoss 7, JPA 2.0 with Hibernate as persistence provider and a PostgreSQL 9.1 database. EDIT : I found the cause of my problem. Apparently it is due to the way I defined the primary key

Hibernate/JPA ManyToOne vs OneToMany

由 左心房为你撑大大i 提交于 2019-11-26 17:57:58
问题 I am reading currently the documentation of Hibernate regarding the entity associations and I come accross a little difficulty to figure out some things. It has to do in essence with the difference between ManyToOne and OneToMany associations. Although I have used them in real projects, I cannot apprehend completely the differnce between them. To my understanding, if a table / an entity has a ManyToOne association with another, then the association should be from the other side OneToMany . So

JPA: unidirectional many-to-one and cascading delete

由 心已入冬 提交于 2019-11-26 17:10:51
Say I have a unidirectional @ManyToOne relationship like the following: @Entity public class Parent implements Serializable { @Id @GeneratedValue private long id; } @Entity public class Child implements Serializable { @Id @GeneratedValue private long id; @ManyToOne @JoinColumn private Parent parent; } If I have a parent P and children C 1 ...C n referencing back to P, is there a clean and pretty way in JPA to automatically remove the children C 1 ...C n when P is removed (i.e. entityManager.remove(P) )? What I'm looking for is a functionality similar to ON DELETE CASCADE in SQL. Vineet

IllegalStateException with Hibernate 4 and ManyToOne cascading

由 孤者浪人 提交于 2019-11-26 14:19:55
问题 I've got those two classes MyItem Object: @Entity public class MyItem implements Serializable { @Id private Integer id; @ManyToOne(cascade = {CascadeType.PERSIST, CascadeType.MERGE}) private Component defaultComponent; @ManyToOne(cascade = {CascadeType.PERSIST, CascadeType.MERGE}) private Component masterComponent; //default constructor, getter, setter, equals and hashCode } Component Object: @Entity public class Component implements Serializable { @Id private String name; //again, default

JPA OneToMany and ManyToOne throw: Repeated column in mapping for entity column (should be mapped with insert=“false” update=“false”)

由 南笙酒味 提交于 2019-11-26 10:26:53
问题 I have three classes one of the name is User and this user have other classes instances. Like this; public class User{ @OneToMany(fetch=FetchType.LAZY, cascade = CascadeType.ALL) public List<APost> aPosts; @OneToMany(fetch=FetchType.LAZY, cascade = CascadeType.ALL) public List<BPost> bPosts; } public class BPost extends Post { @ManyToOne(fetch=FetchType.LAZY) public User user; } public class APost extends Post { @ManyToOne(fetch=FetchType.LAZY) public User user; } it\'s working like this but

JPA: unidirectional many-to-one and cascading delete

由 你说的曾经没有我的故事 提交于 2019-11-26 05:17:05
问题 Say I have a unidirectional @ManyToOne relationship like the following: @Entity public class Parent implements Serializable { @Id @GeneratedValue private long id; } @Entity public class Child implements Serializable { @Id @GeneratedValue private long id; @ManyToOne @JoinColumn private Parent parent; } If I have a parent P and children C 1 ...C n referencing back to P, is there a clean and pretty way in JPA to automatically remove the children C 1 ...C n when P is removed (i.e. entityManager

What is the meaning of the CascadeType.ALL for a @ManyToOne JPA association

由 心已入冬 提交于 2019-11-26 00:57:02
问题 I think I misunderstood the meaning of cascading in the context of a @ManyToOne relationship. The case: public class User { @OneToMany(fetch = FetchType.EAGER) protected Set<Address> userAddresses; } public class Address { @ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL) protected User addressOwner; } What is the meaning of the cascade = CascadeType.ALL ? For example, if I delete a certain address from the database, how does the fact that I added the cascade = CascadeType.ALL

What is the meaning of the CascadeType.ALL for a @ManyToOne JPA association

由 余生长醉 提交于 2019-11-25 23:42:16
I think I misunderstood the meaning of cascading in the context of a @ManyToOne relationship. The case: public class User { @OneToMany(fetch = FetchType.EAGER) protected Set<Address> userAddresses; } public class Address { @ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL) protected User addressOwner; } What is the meaning of the cascade = CascadeType.ALL ? For example, if I delete a certain address from the database, how does the fact that I added the cascade = CascadeType.ALL affect my data (the User , I guess)? The meaning of CascadeType.ALL is that the persistence will propagate
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