Question

我有用户（员工）的数据库

@Entity
@Table(name = "user")

public class User {

public enum Role{
    USER,ADMIN
}

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
@Column(name = "first_name", nullable = false)
private String firstName;
@Column(name = "last_name", nullable = false)
private String lastName;
@Column(name = "email", nullable = false, unique = true)
private String email;
@Column(name = "password", nullable = false)
private String password;
@Column(name = "company", nullable = false)
private String company;
private String title;
@Enumerated(EnumType.STRING)
@Column(name = "role", nullable = false)
private Role role = Role.USER;


public User() {
}

public User(String firstName, String lastName, String email, String password, String company, String title)

        {
    this.firstName = firstName;
    this.lastName = lastName;
    this.email = email;
    this.password = password;
    this.company = company;
    this.title = title;
     }

我有UserDao.java

@Repository
public interface UserDao extends JpaRepository<User,Long> {
User findByEmail(String email);
}

当然还有UserController.java

@RequestMapping(value = "/edit-active-user/{email:.+}", method = RequestMethod.GET)
public String editActiveUserAgainGet(@PathVariable String email, Model model) {

    System.out.println(email.toString());
    User user = userDao.findByEmail(email);
    model.addAttribute("user", user);
    return "editUser";
}

@RequestMapping(value = "/edit", method = RequestMethod.POST)
public String saveUserAgain(@ModelAttribute User user) {

    userDao.save(user);

    return "redirect:/";
}

在名为editUser的jsp文件中，我的表单包含例如：

<div class="form-group">
                    <label class="control-label col-sm-2" for="title">Title:</label>
                    <div class="col-sm-6">
                        <input required value="${user.title}" name="title" type="text" id="title" class="form-control" placeholder="Enter your job title" autofocus>
                    </div>
                </div>

根据每个用户的属性无密码。

在更新属性期间，所有属性都会再次保存（甚至其中一些还没有更改）但密码为NULL，因为它不是JSP格式。

Answer 1

如果您想要更新，我们只说一个字段，那么您可以在存储库中编写另一个带有@Query和@Modifying注释的方法，例如：

@Modifying
@Query("update user u set u.email = ?1 where u.id = ?2")
int setEmail(String email, Long id);

这是documentation。

Answer 2

也许你需要传递hibernate dynamic-update = true。有关详细信息，请阅读以下https://www.mkyong.com/hibernate/hibernate-dynamic-update-attribute-example/

<强>更新

DECLARE @sampledata AS TABLE 
(
CustomerID int,      
ProductID  int
)

INSERT INTO @sampledata VALUES (111, 6577),(111,6123  ),(111,1133 ),(111 ,1133)

SELECT *, 
       CONCAT(s.CustomerID,'-',CAST(dense_rank() over(PARTITION BY s.CustomerID ORDER BY s.ProductID DESC) AS varchar(10))) AS ref
FROM @sampledata s

如果您传递updatable false，它将永远不会在更新中使用，仅在插入中使用。

如何使用DAO仅更新数据库中的一个字段

2 个答案: