I have two entity types in Spring with a relationship:
#Entity
public class Domain {
public Domain() {}
#Id
#GeneratedValue(strategy= GenerationType.IDENTITY)
#Column(name = "id")
private Integer id;
private String name;
private String description;
private String image;
#OneToMany(cascade=CascadeType.ALL, targetEntity=Subdomain.class,fetch = FetchType.LAZY)
#JoinColumn(name="domain_id")
private Set<Subdomain> subdomain = new HashSet<>();
//Default getters and setters
}
And the type subdomain:
#Entity
public class Subdomain {
public Subdomain() {}
#Id
#GeneratedValue(strategy= GenerationType.IDENTITY)
#Column(name = "id")
private Integer id;
private String name;
#JsonIgnore
#OneToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "domain_id", nullable = false)
public Domain domain;
//Default getters and setters
}
This works perfect with a get request, the relation is fetched. But how does it works with post request? I would create a new subdomain with the relationship to an existing domain:
"domain_id": "2"
And this:
"domain_id": "http://localhost/subdomain/2"
But this doesn't work. What is the best way to solve this?
Could not execute statement; SQL [n/a]; constraint [null]; nested exception is org.hibernate.exception.ConstraintViolationException: could not execute statement
Related
I have to entities modeled Session and Speaker, with ManyToMany relationship, and I wanted to delete an instance of Session, but in the DB it is the foreign key of another table. Below is the entity model
#Entity(name = "sessions")
public class Session {
// attributes do not respect camel case notations because they
// need to match table notations in order to auto bind without annotations
// otherwise that is done with #Column annotation
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long session_id;
private String session_name;
private String session_description;
private String session_length;
#OnDelete(action = OnDeleteAction.CASCADE)
#ManyToMany()
#JoinTable(
name = "session_speakers",
joinColumns = #JoinColumn(name = "session_id"),
inverseJoinColumns = #JoinColumn(name = "speaker_id")
)
private List<Speaker> speakers;
public Session() {
}
I tried to use OnDelete Cascade, but it still didn't work. (I did read that it is not advised to use on ManyToMany relationship)
#RequestMapping(value = "{id}", method = RequestMethod.DELETE)
public void delete(#PathVariable Long id){
sessionRepo.deleteById(id);
}
EDIT:
here is also the Speaker entity
#Entity(name = "speakers")
public class Speaker {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long speaker_id;
private String first_name;
private String last_name;
private String title;
private String company;
private String speaker_bio;
#Lob
#Type(type = "org.hibernate.type.BinaryType")
private Byte[] speaker_photo;
public Byte[] getSpeaker_photo() {
return speaker_photo;
}
public void setSpeaker_photo(Byte[] speaker_photo) {
this.speaker_photo = speaker_photo;
}
#ManyToMany(mappedBy = "speakers")
#JsonIgnore// added to resolve serialization issues
private List<Session> sessions;
I need to fetch names of all students who have enrolled for the courses.
Url:-/students/{course1}/{course2}
Eg /students/java/oracle
How to write controller, service and repository in rest api.
Entity:-
Student
Integer Id,String name and list coursenames
What about?
#Controller
#RequestMapping("/students")
public class StudentController {
#Autowired
private StudentService studentService;
// /students/java,oracle
#GetMapping(value="/{courses}")
#ResponseBody
public String getStudents(#PathVariable String[] courses) {
return studentService.getStudents(courses);
}
}
Student
#Entity
#Table(name = "student")
public class StudentDao {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private Long id;
#Column(name = "name")
private String name;
#OneToMany(fetch = FetchType.EAGER)
#Fetch(value = FetchMode.SUBSELECT)
#JoinColumn(name = "id", referencedColumnName = "id")
private List<CourseDao> course;
}
Course
#Entity
#Table(name = "course")
public class CourseDao {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private Long id;
#Column(name = "name")
private String name;
}
In my opinion it is bad rest design. I'll create POST endpoint with body, which contains array with course Id's and find students by course id's.
If the parameters are optional or an array you shouldn't use a path variable but use a request parameter.
Click Link for pic
Please help I am stuck in error after error
Need to create a spring data model and pass the test case
Spring data models are
#Entity
public class Cart {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Integer cartId;
private Double totalAmount;
#OneToOne
#JoinColumn(name = "userId")
private User user;
#OneToMany(mappedBy = "cart")
private List<CartProduct> cartProducts;
//getter and setter and constructor
}
#Entity
public class CartProduct {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Integer cpId;
#ManyToOne
#JoinColumn(name = "cartId")
private Cart cart;
#ManyToOne
#JoinColumn(name = "productId")
private Product product;
private Integer quantity = 1;
//getter and setter and constructor
}
#Entity
public class Category {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Integer categoryId;
private String categoryName;
//getter and setter and constructor
}
#Entity
public class Product {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Integer productId;
private String productName;
private Double price;
#ManyToOne
#JoinColumn(name ="userId")
private User seller;
#ManyToOne
#JoinColumn(name ="userId")
private Category category;
//getter and setter and constructor
}
The main issue is role and user can't able to create
many-to-many relations
#Entity
public class Role {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
Integer roleId;
String role;
#ManyToMany(mappedBy = "roles")
Set<User> users = new HashSet<>();
//getter setter and constructor
}
#Entity
public class User {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Integer userId;
private String username;
private String password;
// Implement Roles
#ManyToMany
#JoinTable(name="user_Role",joinColumns = #JoinColumn(name="userId")
,inverseJoinColumns = #JoinColumn(name="roleId"))
private Set<Role> roles = new HashSet<Role>();
}
https://pastebin.com/T34SbwMy
the test case is in the link and can't able to pass the test case.
Thanks in advance.
I use OneToOne in the spring data JPA and I want to delete a record from the Address table without touching the user. But I can't.
If I remove User, in this case Address is removed, that's good.
But how can you delete an Address without touching the User?
https://github.com/myTestPercon/TestCascade
User.Java
#Entity
#Table(name = "user", schema = "testCascade")
public class User implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private Long id;
#Column(name = "name")
private String name;
#OneToOne(mappedBy = "user", cascade = CascadeType.ALL)
private Address address;
// Getter and Setter ...
}
Address.java
#Entity
#Table(name = "address", schema = "testCascade")
public class Address implements Serializable {
#Id
private Long id;
#Column(name = "city")
private String city;
#OneToOne
#MapsId
#JoinColumn(name = "id")
private User user;
// Getter and Setter ...
}
DeleteController.java
#Controller
public class DeleteController {
#Autowired
ServiceJpa serviceJpa;
#GetMapping(value = "/deleteAddressById")
public String deleteAddressById () {
serviceJpa.deleteAddressById(4L);
return "redirect:/home";
}
}
You got your mapping wrong thats all is the problem .
try the below and see
User.java
#Entity
#Table(name = "user", schema = "testCascade")
public class User implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private Long id;
#Column(name = "name")
private String name;
#OneToOne(cascade=CascadeType.ALL)
#JoinColumn(name="foriegn key column in user table for address example.. address_id")
private Address address;
// Getter and Setter ...
}
Address.java
#Entity
#Table(name = "address", schema = "testCascade")
public class Address implements Serializable {
#Id
private Long id;
#Column(name = "city")
private String city;
//name of the address variable in your user class
#OneToOne(mappedBy="address",
cascade={CascadeType.DETACH, CascadeType.MERGE, CascadeType.PERSIST,
CascadeType.REFRESH})
private User user;
// Getter and Setter ...
}
In order to solve this problem, you need to read the hibernate Documentation Hibernate Example 162, Example 163, Example 164.
And also I recommend to look at this is Using #PrimaryKeyJoinColumn annotation in spring data jpa
This helped me in solving this problem.
And also you need to specify the parameter orphanRemoval = true
User.java
#Entity(name = "User")
#Table(name = "user", schema = "testother")
public class User implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id")
private Long id;
#Column(name = "name")
private String name;
#OneToOne(mappedBy = "user", cascade = CascadeType.ALL, orphanRemoval = true)
private Address address;
public void addAddress(Address address) {
address.setUser( this );
this.address = address;
}
public void removeAddress() {
if ( address != null ) {
address.setUser( null );
this.address = null;
}
}
// Getter and Setter
}
Address.java
#Entity(name = "Address")
#Table(name = "address", schema = "testother")
public class Address implements Serializable {
#Id
private Long id;
#Column(name = "city")
private String city;
#OneToOne
#MapsId
#JoinColumn(name = "id")
private User user;
// Getter and Setter
}
DeleteController .java
#Controller
public class DeleteController {
#Autowired
ServiceJpa serviceJpa;
#GetMapping(value = "/deleteUser")
public String deleteUser () {
User user = serviceJpa.findUserById(2L).get();
user.removeAddress();
serviceJpa.saveUser(user);
return "/deleteUser";
}
}
Or make a custom SQL query.
#Repository
public interface DeleteAddress extends JpaRepository<Address, Long> {
#Modifying
#Query("delete from Address b where b.id=:id")
void deleteBooks(#Param("id") Long id);
}
public class Address {
#Id
private Long id;
#MapsId
#JoinColumn(name = "id")
private User user;
}
Rename #JoinColumn(name = "id") to #JoinColumn(name = "user_id")
You can't say that the column that will point to user will be the id of the Address
I have two entities in one to many relationship in my spring-data-jpa project.
Parent entity -
#Entity
#Table(name = "code_group")
public class CodeGroup implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.SEQUENCE)
private Long id;
#NaturalId
#Column(nullable = false)
private String entityId;
#OneToMany
#JoinColumn(name = "codeGroupId", referencedColumnName = "entityId")
private List<SystemCode> systemCodes;
// .. getters setters
}
Child entity -
#Entity
#Table(name = "system_code")
public class SystemCode implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.SEQUENCE)
private Long id;
#Column(nullable = false)
private String codeGroupId;
#Column(nullable = false)
#Enumerated(EnumType.STRING)
private ActiveOrInactive status;
// getters and setters
}
status column is of enum type, it can only have Active or Inactive value.
My existing code works fine. It is fetching code group with associated system codes. I want to filter system code with status='Active'. How to do this?
Try like this:
#OneToMany
#JoinColumn(name = "codeGroupId", referencedColumnName = "entityId")
#Where(clause = "status= 'Active'")
private List<SystemCode> systemCodes;
You can create such methods in your repo:
List<CodeGroup> getAllBySystemCodes_Status(ActiveOrInactive status);
default List<CodeGroup> getAllActive() {
return getAllBySystemCodes_Status(ActiveOrInactive.Active);
}
default List<CodeGroup> getAllInactive() {
return getAllBySystemCodes_Status(ActiveOrInactive.Inactive);
}