使用hibernate的场景的实体类

Question

脚本

1. 获取特定订单的产品详细信息。
2. 获取特定产品的订单详细信息。

SQL服务器表

1. Table_Orders
2. Table_OrderDetails
3. Table_Products

实体类

1. Model_orders

   @Entity
   @Table(name="Tbl_Orders")
   public class Order
   {
       public Order() {
       }
   
       @Id
       @GeneratedValue(strategy=GenerationType.IDENTITY)
       @Column(name="Order_ID")
       private Long orderId;
   
       @Column(name="OrderNo")
       private String orderNumber;
   
       @Column(name="OrderDate")
       private Date orderDate;
   
       @ManyToOne()
       @JoinColumn(name="User_ID")
       private Customer customerOrder;
   
   
   
       public Long getOrderId() {
           return orderId;
       }
   
       public void setOrderId(Long orderId) {
           this.orderId = orderId;
       }
   
       public String getOrderNumber() {
           return orderNumber;
       }
   
       public void setOrderNumber(String orderNumber) {
           this.orderNumber = orderNumber;
       }
   
       public Date getOrderDate() {
           return orderDate;
       }
   
       public void setOrderDate(Date orderDate) {
           this.orderDate = orderDate;
       }
   
       public Customer getCustomerOrder() {
           return customerOrder;
       }
   
       public void setCustomerOrder(Customer customerOrder) {
           this.customerOrder = customerOrder;
       }
   }

2. Model_OrderDetails

   @Entity
   @Table(name = "Tbl_OrderDetails")
   public class OrderDetail {
   
       public OrderDetail() {
           super();
       }
   
       @Id
       @GeneratedValue(strategy = GenerationType.IDENTITY)
       @Column(name = "OrderDetail_ID")
       private Long orderDetailsId;
   
       @ManyToOne
       @JoinColumn(name = "Order_ID")
       private Order orderId;
   
       @ManyToOne
       @JoinColumn(name = "Product_ID")
       private ProductMaster product;
   
   
       public Long getOrderDetailsId() {
           return orderDetailsId;
       }
   
       public void setOrderDetailsId(Long orderDetailsId) {
           this.orderDetailsId = orderDetailsId;
       }
   
       public Order getOrderId() {
           return orderId;
       }
   
       public void setOrderId(Order orderId) {
           this.orderId = orderId;
       }
   
   
   
       public ProductMaster getProduct() {
           return product;
       }
   
       public void setProduct(ProductMaster product) {
           this.product = product;
       }
   }

3. Model_Products

   @Entity
   @Table (name = "Tbl_Products")
   public class ProductMaster
   {
       public Products() {
       }
   
       @Id
       @GeneratedValue(strategy=GenerationType.IDENTITY)
       @Column (name = "Product_ID")
       @Field(index= Index.YES, analyze= Analyze.YES, store= Store.YES)
       private Long productId;
   
       @Column (name = "Product_Code")
       private String productCode;
   
       @Column (name = "Product_Name")
       @Field(index= Index.YES, analyze= Analyze.YES, store= Store.YES  ,analyzer=@Analyzer(definition = "customanalyzer"))
       private String productName;
   
   
   
       public Long getProductId() {
           return productId;
       }
   
       public void setProductId(Long productId) {
           this.productId = productId;
       }
   
   
       public String getProductCode() {
           return productCode;
       }
   
       public void setProductCode(String productCode) {
           this.productCode = productCode;
       }
   
       public String getProductName() {
           return productName;
       }
   
       public void setProductName(String productName) {
           this.productName = productName;
       }
   }

问题描述

在这个实体类中，我在所有三个类中使用了多对一映射。我上面提到的场景很多。一个订单可以有多个产品，同时一个产品可以放在许多订单中。

我的问题是使用订单ID我需要获取所有产品详细信息。同样使用产品ID我需要获取所有订单详细信息。我想在细节实体类中使用一对多映射，但我不知道如何映射它。这是正确的方法吗？

Answer 1

在您的代码中，Table_OrderDetails的目的只是在Order_ID和Product_ID之间创建一个映射。因此，不应将其创建为分离的“实体”。应该使用Hibernates @ManyToMany。

order.Java

import javax.persistence.*;
import java.sql.Date;
import java.util.ArrayList;
import java.util.List;

@Entity
@Table(name="Tbl_Orders")
public class Order
{
    public Order() {
    }
    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    @Column(name="Order_ID")
    private Long orderId;

    @Column(name="OrderNo")
    private String orderNumber;

    @Column(name="OrderDate")
    private Date orderDate;

    @ManyToMany
    @JoinTable(name = "Tbl_OrderDetails",
            joinColumns = @JoinColumn(name = "Order_ID"),
            inverseJoinColumns = @JoinColumn(name = "Product_ID"))
    private List<ProductMaster> productMasters = new ArrayList<>();

    public Long getOrderId() {
        return orderId;
    }

    public void setOrderId(Long orderId) {
        this.orderId = orderId;
    }

    public String getOrderNumber() {
        return orderNumber;
    }

    public void setOrderNumber(String orderNumber) {
        this.orderNumber = orderNumber;
    }

    public Date getOrderDate() {
        return orderDate;
    }

    public void setOrderDate(Date orderDate) {
        this.orderDate = orderDate;
    }

    public List<ProductMaster> getProductMasters() {
        return productMasters;
    }

    public void setProductMasters(List<ProductMaster> productMasters) {
        this.productMasters = productMasters;
    }
}

product master.Java

import javax.persistence.*;
import java.util.ArrayList;
import java.util.List;

@Entity
@Table(name = "Tbl_Products")
public class ProductMaster
{
    public ProductMaster() {
    }

    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    @Column (name = "Product_ID")
    private Long productId;

    @Column (name = "Product_Code")
    private String productCode;

    @Column (name = "Product_Name")
    private String productName;

    @ManyToMany(mappedBy = "productMasters")
    private List<Order> orders = new ArrayList<>();

    public Long getProductId() {
        return productId;
    }

    public void setProductId(Long productId) {
        this.productId = productId;
    }


    public String getProductCode() {
        return productCode;
    }

    public void setProductCode(String productCode) {
        this.productCode = productCode;
    }

    public String getProductName() {
        return productName;
    }

    public void setProductName(String productName) {
        this.productName = productName;
    }

    public List<Order> getOrders() {
        return orders;
    }

    public void setOrders(List<Order> orders) {
        this.orders = orders;
    }
}

这将自动创建包含Id列的第三个表'Tbl_OrderDetails'。您将能够获得一个产品的所有订单，以及一个订单中的所有产品。

Answer 2

获取特定订单的产品详细信息。

创建Order到OrderDetail的双向映射。

Into Order:
@OneToMany(cascade = CascadeType.ALL, mappedBy = "orderId", fetch = FetchType.LAZY)
private Collection<OrderDetail> ordersDetail;

获取特定产品的订单详细信息。

创建ProductMaster到OrderDetail的双向映射。

Into ProductMaster:
@OneToMany(cascade = CascadeType.ALL, mappedBy = "product", fetch = FetchType.LAZY)
private Collection<OrderDetail> ordersDetail;