英文:
I'm not getting distinct ID's for nested resources in REST api
问题
以下是您提供的内容的中文翻译：
我正在编写一个ContactManager的REST API，其中包括ContactGroup和Contact实体。Contact实体嵌套在ContactGroup中。我想要在每个ContactGroup内生成从1开始递增的联系人Id，并且独立于其他ContactGroup的联系人。
但是，在我的代码中，每个特定ContactGroup中创建的新联系人的Id生成取决于其他ContactGroup中最后一个创建的联系人的Id。
例如，如果有两个contactGroupId为1、2的ContactGroup。我已经在contactGroupId为1的ContactGroup中创建了2个联系人，其contactId分别为1和2。然后，在创建contactGroupId为2的ContactGroup中的新联系人时，生成的contactId是3，但应该生成为1。
我正在添加这两个实体：
ContactGroup.java
@Entity
public class ContactGroup {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long groupId;
private String name;
private String description;
@OneToMany(targetEntity = Contact.class, fetch = FetchType.LAZY, cascade = CascadeType.ALL)
@JsonIgnore
private List<Contact> contacts;
private Integer numberOfContacts;
public ContactGroup() {
}
public ContactGroup(String name, String description) {
this.name = name;
this.description = description;
}
// getters & setters
}
Contact.java
@Entity
public class Contact {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long contactId;
private String name;
private String email;
private Long phoneNumber;
private String address;
@ManyToOne(targetEntity = ContactGroup.class, fetch = FetchType.LAZY, cascade = CascadeType.ALL)
@JsonIgnore
private ContactGroup contactGroup;
public Contact() {
}
public Contact(String name, String email, Long phoneNumber, String address) {
this.name = name;
this.email = email;
this.phoneNumber = phoneNumber;
this.address = address;
}
// getters & setters
}
请帮我解决这个问题。任何帮助都将不胜感激。
英文:
I am writing a REST api of ContactManager, which consists of ContactGroup and Contact entity. The Contact entity is nested in ContactGroup. I want to generate Id of contacts within each ContactGroup starting with 1 and increases sequentially and is independent of other Contact group's contacts.
But, In my code the Id generation of each new contact created in a particular ContactGroup is dependent on the Id of last contact created in other ContactGroup.
For example, If there is two ContactGroup with contactGroupId: 1,2. And I have created 2 contacts in ContactGroupId: 1 with contactId: 1 & 2. Then while creating new contact in ContactGroupId: 2, the contactId generated is 3 but it should be generated as 1.
I am adding the both entities:
ContactGroup.java
@Entity
public class ContactGroup {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long groupId;
private String name;
private String description;
@OneToMany(targetEntity = Contact.class, fetch = FetchType.LAZY, cascade = CascadeType.ALL)
@JsonIgnore
private List<Contact> contacts;
private Integer numberOfContacts;
public ContactGroup() {
}
public ContactGroup(String name, String description) {
this.name = name;
this.description = description;
}
//getters & setters
}
Contact.java
@Entity
public class Contact {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long contactId;
private String name;
private String email;
private Long phoneNumber;
private String address;
@ManyToOne(targetEntity = ContactGroup.class, fetch = FetchType.LAZY, cascade = CascadeType.ALL)
@JsonIgnore
private ContactGroup contactGroup;
public Contact() {
}
public Contact(String name, String email, Long phoneNumber, String address) {
this.name = name;
this.email = email;
this.phoneNumber = phoneNumber;
this.address = address;
}
// getters & setters
}
Kindly, help me out in solving this problem. Any help would be appreciated.
答案1
得分: 0
Contact.contactId是主键，它必须在所有联系人中是唯一的。您不能在不同的联系人组中拥有具有相同id的联系人。
您可以通过使用复合id（contactId，contactGroup）和自定义生成器来实现您的目标，但我不确定这是否是一个好主意。
英文:
Contact.contactId is a primary key, it must be unique for all contacts. You cannot have contacts with the same id in different contact groups.
You could achieve your goal by using a composite id (contactId, contactGroup) and custom generator for the contactId, but I'm not sure it's a good idea.
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