Developing an application of shopping cart below are my entity classes....
When i save it for the first time user entity is saved properly when same request is used to save user again then previously saved foreign key is becoming null i am using same request because, for same user, for same cart ,cart products have to updated in multiple rows.
@Entity
public class CartProduct implements Serializable {
/**
* serialVersionUID.
*/
private static final long serialVersionUID = 5846027470952949766L;
/**
* cartProdcutId.
*/
@Id
@GeneratedValue
@Column(name = "CART_PRODUCT_ID")
private Integer cartProdcutId;
/**
* product.
*/
@ManyToOne
@JoinColumn(name = "PRODUCT_ID")
private Product product;
/**
* cart.
*/
@ManyToOne
@JoinColumn(name = "CART_ID")
private Cart cart;
/**
* quantity.
*/
@Min(value = 0, message = "Product Quantity should not be negative")
@Column(name = "QUANTITY")
private Integer quantity;
}
second class
@Entity
public class Cart {
/**
* cartId.
*/
@Id
@GeneratedValue
@Column(name = "CART_ID")
Integer cartId;
/**
* cartProducts.
*/
@OneToMany(cascade = CascadeType.ALL)
@JoinColumn(name = "CART_ID")
Set<CartProduct> cartProducts = new HashSet<CartProduct>();
}
Saving User class
@Entity
public class User {
/**
* userId.
*/
@Id
@GeneratedValue
@Column(name = "USER_ID")
Integer userId;
/**
* userName.
*/
@Column(name = "USER_NAME")
String userName;
/**
* cart.
*/
@OneToOne(cascade = CascadeType.ALL)
Cart cart;
}
Product Class
@Entity
@Inheritance(strategy = InheritanceType.JOINED)
@NamedQueries({ @NamedQuery(name = "Product.findBook", query = "SELECT p FROM Product p WHERE TYPE(p) = Book"),
@NamedQuery(name = "Product.findApparal", query = "SELECT p FROM Product p WHERE TYPE(p) = Apparal"),
@NamedQuery(name = "Product.findByName", query = "SELECT p FROM Product p WHERE p.productName=:name") })
public class Product {
/**
* productId.
*/
@Id
@GeneratedValue
@Column(name = "PRODUCT_ID")
Integer productId;
/**
* productName.
*/
@Column(name = "PRODUCT_NAME")
String productName;
/**
* price.
*/
@Column(name = "PRICE")
Float price;
}
Service method to save User
userRepository.save(user);
Json used in postman to save User entity:
{
"cart": {
"cartId": 1,
"products": [
{
"cartProdcutId": 1,
"product": {
"price": 100,
"productId": 1,
"productName": "ProdNameOne"
},
"quantity": 1
}
]
},
"userId": 1,
"userName": "USERONE"
}
Below is the data base screen shot where null is updated in first row :Data base screen shot
