如何在SpringMVC的@joincolumn中插入数据

Question

我有两个表customerdetails和product，我想从cocers表中添加它> @joincolumn（order_id） customerdetails表中的列。

customerDetails.java

@Entity
@Table(name = "CustomerDetails")
public class CustomerDetails {

    @Id
    @GeneratedValue
    @Column(name="CUSTOMER_ID")
    private Long custid;

    @Column(name="CUSTOMER_NAME")
    private String customerName;
    
    @Column(name="EMAIL")
    private String email;
    
    @Column(name="ADDRESS")
    private String address;
    
    @Column(name="PHONENO")
    private String phoneno;
    
    public CustomerDetails() {
    }

    @Override
    public String toString() {
        return "CustomerDetails [custid=" + custid + ", customername=" + customerName + ", email=" + email
                + ", address=" + address + ", phoneno=" + phoneno + "]";
    }

    public CustomerDetails(String customername, String email, String address, String phoneno) {
        super();
        this.customerName = customername;
        this.email = email;
        this.address = address;
        this.phoneno = phoneno;
    }   
    public Long getCustid() {
        return custid;
    }

    public void setCustid(Long custid) {
        this.custid = custid;
    }

    public String getName() {
        return customerName;
    }

    public void setName(String name) {
        this.customerName = name;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getPassword() {
        return address;
    }

    public void setPassword(String password) {
        this.address = password;
    }

    public String getPhoneno() {
        return phoneno;
    }

    public void setPhoneno(String phoneno) {
        this.phoneno = phoneno;
    }   
}

product.java

@Entity
@Table(name="Product")
public class Product {
    
    @Id
    @GeneratedValue
    @Column(name="PRODUCT_ID")
    private Long productId;
    
    @Column(name="PRODUCT_NAME")
    private String productName;
    
    @Column(name="PRODUCT_BRAND")
    private String productBrand;
    
    @Column(name="PRODUCT_PRICE")
    private double productPrice;
    
    @OneToOne
    private CustomerDetails cd;
   
    public Product(Long productId, String productName, String productBrand, double productPrice, CustomerDetails cd) {
        super();
        this.productId = productId;
        this.productName = productName;
        this.productBrand = productBrand;
        this.productPrice = productPrice;
        this.cd = cd;
    }
    
    public Product(String productName, String productType, double productPrice) {
        super();
        this.productName = productName;
        this.productBrand = productType;
        this.productPrice = productPrice;
    }
    
    public Long getProductId() {
        return productId;
    }
    public void setProductId(Long productId) {
        this.productId = productId;
    }
    public String getProductName() {
        return productName;
    }
    public void setProductName(String productName) {
        this.productName = productName;
    }
    public String getProductBrand() {
        return productBrand;
    }
    public void setProductBrand(String productType) {
        this.productBrand = productType;
    }
    public double getProductPrice() {
        return productPrice;
    }
    public void setProductPrice(double productPrice) {
        this.productPrice = productPrice;
    }
    
    public CustomerDetails getCd() {
        return cd;
    }

    public void setCd(CustomerDetails cd) {
        this.cd = cd;
    }
    public Product() {
        //super();
    }
    @Override
    public String toString() {
        return "Product [productId=" + productId + ", productName=" + productName + ", productType=" + productBrand
                + ", productPrice=" + productPrice + "]";
    }
 
}

customerDetails

@Repository
public interface CdRepo extends JpaRepository<CustomerDetails, Long>
{
            
}

使用getCustid（）我现在获得了

@Repository
public interface ProductRepo extends JpaRepository<Product, Long>
{
        
}

客户的ID ，

@Service
@Transactional
public class CustomerService  {
    
    private final CdRepo cdRepo;
    
    @Autowired
    public CustomerService(CdRepo cdRepo) {
        
        this.cdRepo = cdRepo;
        
    }
    public void saveCustomer(CustomerDetails cd) 
    {
        cdRepo.save(cd);
            
    }   
}

当前

@RequestMapping(value = {"/addCustomerDetails"}, method = RequestMethod.POST)
    public ModelAndView addCustomerDetails(CustomerDetails cd) 
    {
        
        customerService.saveCustomer(cd);
        System.out.println(cd.getCustid());
        ModelAndView model = new ModelAndView();
        model.setViewName("homepage");
        return model;
    }

我想将该ID插入@joincolumn（order_id）

Answer 1

如果我正确理解，则要将产品分配给用户（例如客户）。
对于@OnetoOne关系，您不需要private customerdetails cd;在产品类中。尽管我不知道为什么您会以这种方式实施这种事情！

通常，如果您想将两件事分配在一起，假设您想将产品分配给用户，以便该产品适合该用户，则应从存储库或任何地方找到product obj产品和用户都必须具有DB生成的ID），然后将其分配给user.product。

产品服务

@Service
public class ProductService  {

  @Autowired
  private ProductRepo productRepository;

  public Optional<Product> findProductById(Long id) {
     return this.productRepository.findByProductId(id);
  }  

}

客户服务

@Service
@Transactional
public class CustomerService  {

  private final CdRepo cdRepo;

  @Autowired
  public CustomerService(CdRepo cdRepo) {
    this.cdRepo = cdRepo;
  }

  public CustomerDetails saveCustomer(CustomerDetails cd, Long productId) {
    CustomerDetails dbCustomer = customerService.saveCustomer(cd);
    // I'm getting the id from path variable, change it if you have other logics
    Optional<Product> dbProduct = this.productService.findProductById(productId);
    // I don't know how you handle run time errors so I can't write it, don't
    // forget to check the dbProduct in case it didn't exist :)
    
    // In case you did not created getters and setters in CustomerDetails,
    // use dbCustomer.product = dbProduct.get();
    dbCustomer.setProduct(dbProduct.get());

    // update our customer using JPA, after customer update JPA handles everything
    return this.cdRepo.save(dbCustomer);
        
  }  

}

控制器

@RequestMapping(value = {"/addCustomerDetails/{productId}"}, method = RequestMethod.POST)
public ModelAndView addCustomerDetails(CustomerDetails cd, @PathVariable Long productId ) 
{
    
    CustomerDetails dbCustomer = this.customerService.saveCustomer(cd, productId);
    // Use the dbCustomer in your logic ...
    ModelAndView model = new ModelAndView();
    model.setViewName("homepage");
    return model;
}

在每个实体中编写Getters和Setter，或使用Lombok注释@Data。
通常，当我想用​​用户和产品部署电子商务时。我使用用户，购物车，产品模型。

上面代码的问题是，如果将该产品分配给用户，则仅适用于该用户。如果其他用户想要相同的产品，则必须为其创建所有这些产品。解决方案将使用产品作为系列或模型。

想象一下您想创建一个网站以出售咖啡包的情况。您只有两种类型的包装可供出售。您可以为这些软件包创建一个类似的产品，并为每个软件包创建数量。然后在购物车模型中创建@onetomany与产品中的关系。它将创建一个JOIN表，以将任何可能的产品ID存储在此处使用CART ID。之后，在您的购物车实体中创建@manytoone关系，@onetomany在您的用户实体中。现在，每个购物车仅适用于特定用户，而不适合产品。

一些友好的建议：

• 不要用逻辑填充控制器。让服务层处理。
• 对于每个实体，创建一个带有实体名称的软件包，然后创建3个类；实体本身，响应Pojo并要求Pojo。
• 将getters和setters用于您的Entites。您可以使用Lombok。它将通过产生情况来处理这种情况。
• 使用转换器组件创建和转换为实体本身，并将实体转换为响应实体。
• 避免尽可能多地与数据库进行交互。将对象放在变量中，例如dbcustomer用于执行操作。