SpringBoot 遇到 No identifier specified for entity

No identifier specified for entity 從字面上不難看出來是沒有設置主鍵

因為沒有為標注為@Entity的實體類注明主鍵

import lombok.Data;
import org.springframework.data.annotation.Id;

import javax.persistence.*;

@Data
@Table(name = "user")
@Entity
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
    @Column
    private String username;
    @Column
    private String name;
    @Column
    private Integer age;
}

 

但實際上bean用@Id和@GenerateValue標注在ID上，仔細觀察發現是導錯包：import org.springframework.data.annotation.Id;這是Spring提供的；而應該導入javax.persistence.Id，很細微的差別，可能不注意看就錯了而且很難去排查問題

區別在於：org.springframework.data.annotation.Id是spring用來支持MongoDB等非關系型數據庫的持久化(spring-data-mongodb等)；javax.persistence.Id適用於關系型的數據