many-to-one

问题 help me find JSON property annotation who give me choose an entity property to JSON serialization. I need only one. I code like that: @Entity @Table(name = "pages") public class Page { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) @Column(name = "id") private Long id; @Column(name = "name") private String name; @JsonIgnoreProperties(value = {"name", "description", "pages"}) // it's working, but I want to simplify, I need only project id property to JSON @ManyToOne(fetch = FetchType

问题 I start showing you my scenario. This is my parent object: @Entity @Table(name="cart") public class Cart implements Serializable{ @GeneratedValue(strategy=GenerationType.IDENTITY) @Id @Column(name="id") private Integer id; @OneToMany(mappedBy="cart", fetch = FetchType.EAGER, cascade = CascadeType.ALL) private List<CartItem> cartItems; ... } This is my child object: @Entity @Table(name="cart_item") public class CartItem implements Serializable{ @GeneratedValue(strategy=GenerationType.IDENTITY)

来源： https://stackoverflow.com/questions/3029760/two-entities-with-manytoone-should-join-the-same-table

来源： https://stackoverflow.com/questions/53504230/kotlin-jpa-lazy-restapi-not-respected

来源： https://stackoverflow.com/questions/63110054/when-creating-credit-cards-for-a-single-user-it-only-updates-the-previous-card

问题 Simply put I have a many to one relation on the Child class with the Parent class. I want to load all the children without having to load their parent details. My child class is @Entity public class Child implements Serializable { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Long id; private String name; @ManyToOne(fetch = FetchType.LAZY) @JoinColumn(name = "parentId", referencedColumnName = "id") private Parent parent; public Child() { } // Getters and setters here } My

问题 I am experiencing something weird when using NHibernate. I have opened up a codebase that I didn't write, and the one who did isn't here anymore. So I guess what I am looking for is more tips on debugging than anything else. I am using NHIbernate 3.4 Linq provider, to query an entity, that has a many-to-one relationship to another entity. What I see is the even though I never access the property that represents the many-to-one relation it is always hydrated. From looking at the queries

问题 I am using Hibernate with spring. I have a model-class like this. @Entity @Table(name = "forumtopic") public final class Forumtopic extends AbstractUserTracking implements java.io.Serializable { /**SNIP **/ private Forumcategory forumcategory; @ManyToOne(fetch = FetchType.LAZY) @JoinColumn(name = "FkForumcategoryId", nullable = false) public Forumcategory getForumcategory() { return this.forumcategory; } public void setForumcategory(final Forumcategory forumcategory) { this.forumcategory =

问题 This is a beginner-level question. I have a catalog of mtypes: mtype_id name 1 'mtype1' 2 'mtype2' [etc] and a catalog of Objects, which must have an associated mtype: obj_id mtype_id name 1 1 'obj1' 2 1 'obj2' 3 2 'obj3' [etc] I am trying to do this in SQLAlchemy by creating the following schemas: mtypes_table = Table('mtypes', metadata, Column('mtype_id', Integer, primary_key=True), Column('name', String(50), nullable=False, unique=True), ) objs_table = Table('objects', metadata, Column(

问题 After days of torture to resolve this issue and reading everything I could find on SO I decided to ask. I'm having trouble understanding what I read here on Hibernate site, so I'll explain my situation. I have object student that contains object program : @ManyToOne(cascade = {CascadeType.PERSIST, CascadeType.MERGE}, fetch=FetchType.EAGER) @JoinColumn(name = "PROGRAM_FK", nullable = false) private Program program; In my service method I want o change/update only program for a student: public