[英]spring data jpa tables joining by One to one Association
我试图连接两个表,并通过使用Spring数据JPA一对一关联来显示其结果。 在下面,我要添加模型和存储库类,我的第一个模型类Users是,
@Entity
@Table(name = "users")
public class Users implements Serializable{
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Integer id;
@Column(name = "username")
public String username;
@Column(name = "password")
public String password;
@Column(name = "privid")
public Integer privid;
@OneToOne()
@JoinColumn(name="join_privillage")
private Privillages priviJoin;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public Integer getPrivid() {
return privid;
}
public void setPrivid(Integer privid) {
this.privid = privid;
}
public Privillages getPriviJoin() {
return priviJoin;
}
public void setPriviJoin(Privillages priviJoin) {
this.priviJoin = priviJoin;
}
protected Users() {
}
public Users(String username, String password, Integer privid) {
this.username = username;
this.password = password;
this.privid = privid;
}
@Override
public String toString() {
return String.format("Users[id=%d, username='%s', password='%s']", id,
username, password);
}
}
我需要加入的下一个Model类是:
@Entity
@Table(name = "privillages")
public class Privillages implements Serializable {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
public Integer id;
@Column(name = "privid")
public Integer privid;
@Column(name = "privi_name")
public String privi_name;
@OneToOne(fetch=FetchType.LAZY, mappedBy="priviJoin")
public Users user;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public Integer getPrivid() {
return privid;
}
public void setPrivid(Integer privid) {
this.privid = privid;
}
public String getPrivi_name() {
return privi_name;
}
public void setPrivi_name(String privi_name) {
this.privi_name = privi_name;
}
public Users getUser() {
return user;
}
public void setUser(Users user) {
this.user = user;
}
public Privillages() {
}
public Privillages(Integer privid, String privi_name ) {
this.privid = privid;
this.privi_name = privi_name;
}
}
我的存储库是:
public interface UsersRepository extends CrudRepository<Users, Integer> {
@Query("SELECT u.username FROM Users u inner join p.privi_name FROM
Privillages p")
List<Users> findByUsername();
}
当我运行应用程序时,它的错误怎么样
“意外令牌:从第1行第74列附近[选择u.username FROM com.central.model.Users内部联接p.privi_name FROM com.central.model.Privillages p]”。
和
“对方法公共抽象java.util.List com.central.repository.UsersRepository.findByUsername()的查询的验证失败!”。
如果您希望获得整个实体,并且已经与用户一起获取了特权,请尝试:
@Query("SELECT u FROM Users u inner join fetch u.priviJoin")
更新资料
如果要使用投影,则必须更改结果类型:
@Query("SELECT u.username,p.privi_name FROM Users u inner join u.priviJoin p")
List<Object[]> findByUsername();
在这种情况下,您也不需要fetch
。
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