Java 与hibernate注释的一对一关系
我有数据库模式的这一部分: 而这个Java 与hibernate注释的一对一关系,java,mysql,database,hibernate,spring-data,Java,Mysql,Database,Hibernate,Spring Data,我有数据库模式的这一部分: 而这个用户实体: @Entity @Table(name = "user", catalog = "ats") public class User implements java.io.Serializable{ private static final long serialVersionUID = 1L; private String username; private boolean enabled; private Role
用户
实体:
@Entity
@Table(name = "user", catalog = "ats")
public class User implements java.io.Serializable{
private static final long serialVersionUID = 1L;
private String username;
private boolean enabled;
private Role role;
private ClientVersion clientVersion;
private ClientLicense clientLicense;
@JsonIgnore
private Set<NotificationHasUser> notificationHasUsers = new HashSet<NotificationHasUser>(0);
public User() {
}
public User(String username, boolean enabled) {
this.username = username;
this.enabled = enabled;
}
public User(String username, boolean enabled, Role role, Set<NotificationHasUser> notificationHasUsers) {
this.username = username;
this.enabled = enabled;
this.role = role;
this.notificationHasUsers = notificationHasUsers;
}
@Id
@Column(name = "username", unique = true, nullable = false, length = 45)
public String getUsername() {
return this.username;
}
public void setUsername(String username) {
this.username = username;
}
@Column(name = "enabled", nullable = false)
public boolean isEnabled() {
return this.enabled;
}
public void setEnabled(boolean enabled) {
this.enabled = enabled;
}
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "id_role", nullable = false)
public Role getRole() {
return this.role;
}
public void setRole(Role role) {
this.role = role;
}
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "id_clientVersion", nullable = false)
public ClientVersion getClientVersion() {
return this.clientVersion;
}
public void setClientVersion(ClientVersion clientVersion) {
this.clientVersion = clientVersion;
}
@OneToMany(fetch = FetchType.LAZY, mappedBy = "pk.user")
public Set<NotificationHasUser> getNotificationHasUser() {
return this.notificationHasUsers;
}
public void setNotificationHasUser(Set<NotificationHasUser> notificationHasUsers) {
this.notificationHasUsers = notificationHasUsers;
}
@OneToOne(fetch = FetchType.LAZY, mappedBy = "user")
public ClientLicense getClientLicense(){
return this.clientLicense;
}
public void setClientLicense(ClientLicense clientLicense){
this.clientLicense = clientLicense;
}
}
这是我的ClientLicense
实体
@Entity
@Table(name = "clientlicense", catalog = "ats")
public class ClientLicense implements java.io.Serializable{
/**
*
*/
private static final long serialVersionUID = 1L;
private Integer idClientLicense;
private Date startDate;
private Date endDate;
private int counter;
private String macAddress;
private String cpuId;
private User user;
public ClientLicense() {
}
/**
* @param startDate
* @param endDate
* @param counter
* @param macAddress
* @param cpuId
* @param users
*/
public ClientLicense(Date startDate, Date endDate, int counter, String macAddress, String cpuId, User user) {
super();
this.startDate = startDate;
this.endDate = endDate;
this.counter = counter;
this.setMacAddress(macAddress);
this.setCpuId(cpuId);
this.user = user;
}
@Id
@GeneratedValue(strategy = IDENTITY)
@Column(name = "id_clientLicense", unique = true, nullable = false)
public Integer getIdClientLicense() {
return this.idClientLicense;
}
public void setIdClientLicense(Integer idClientLicense) {
this.idClientLicense = idClientLicense;
}
@Column(name = "startDate", nullable = false)
public Date getStartDate() {
return this.startDate;
}
public void setStartDate(Date startDate) {
this.startDate = startDate;
}
@Column(name = "endDate", nullable = false)
public Date getEndDate() {
return this.endDate;
}
public void setEndDate(Date endDate) {
this.endDate = endDate;
}
@Column(name = "counter", nullable = false)
public int getCounter() {
return this.counter;
}
public void setCounter(int counter) {
this.counter = counter;
}
/**
* @return the macAddress
*/
@Column(name = "macAddress", nullable = false)
public String getMacAddress() {
return macAddress;
}
/**
* @param macAddress the macAddress to set
*/
public void setMacAddress(String macAddress) {
this.macAddress = macAddress;
}
/**
* @return the cpuId
*/
@Column(name = "cpuId", nullable = false)
public String getCpuId() {
return cpuId;
}
/**
* @param cpuId the cpuId to set
*/
public void setCpuId(String cpuId) {
this.cpuId = cpuId;
}
@OneToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
@JoinColumn(name = "id_username")
public User getUser() {
return this.user;
}
public void setUser(User user) {
this.user = user;
}
}
这是我的第一个
OneToOne
关系,我必须使用的正确注释是什么?我读了一些例子,但我不太明白,它们彼此不同 试试这样的东西
public class User {
private ClientLicense clientLicense;
@OneToOne(fetch = FetchType.LAZY, mappedBy = "user")
public ClientLicense getClientLicense() {
return this.clientLicense;
}
}
public class ClientLicense {
private User user;
@OneToOne
@JoinColumn(name = "id_username")
public User getUser() {
return this.user;
}
}
问题是这两个实体无法发现这两个字段实际上是在指定一个关系。因此,hibernate假定它们不是相同的关系,因此尝试获取它们(因为默认情况下会急切地获取一对一的关系)
在
user
类中的clientLicense
字段之前添加@OneToOne(mappedBy=“user”)
,告诉hibernate该字段与clientLicense
类中的user
字段“映射”在同一列中clientLicense是否需要user
对象?或者它只能使用用户id吗?试着将@JsonIgnore
放在ClientLicense\user
上。我将此注释放在用户类中,它可以工作,但我无法添加新的ClientLicense,我用一个示例更新了我的问题它不工作,无限循环的问题是json注释。@没有@JoinColumn
注释的luca?@JoinColumn在ClientLicense中entity@luca尝试从ClientLicense
中删除@JoinColumn
。没有这个必要mappedBy
应该足够了。这是必要的,否则我会收到com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException:field list@luca中的未知列“clientlice0.user\u username”,这是因为hibernate表已经存在这样一个列。无论如何,这与您的问题无关,代码看起来很好。您是否尝试过删除表并重新创建它们?也许这两列存在于您的表中,而这正是hibernate所困惑的。或者将hibernate设置为update
表定义,而不是使用现有的表定义。
public class User {
private ClientLicense clientLicense;
@OneToOne(fetch = FetchType.LAZY, mappedBy = "user")
public ClientLicense getClientLicense() {
return this.clientLicense;
}
}
public class ClientLicense {
private User user;
@OneToOne
@JoinColumn(name = "id_username")
public User getUser() {
return this.user;
}
}