Question

场景

获取特定订单的产品详细信息。
获取特定产品的订单明细。

SQL服务器表

Table_Orders
Table_OrderDetails
表产品

实体类

型号订单

@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;
    }
}

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;
    }
}

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，同时将一个产品放在多个订单中。

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。我想在订单详细信息实体类中使用一对多映射，但我不知道如何映射它。那是正确的方法吗？

Answer 1

在您的代码中，Table_OrderDetails的目的仅仅是在Order_ID和Product_ID之间创建映射。因此，不应将其创建为单独的“实体”。相反，应使用休眠@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;
    }
}

ProductMaster.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;
    }
}

这将自动创建带有两个Id列的第三个表“ Tbl_OrderDetails”。这样一来，您将可以获取一种产品的所有订单，以及所有产品的同一订单。

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。

ArrayDeque

获取特定产品的订单详细信息。

创建ProductMaster到OrderDetail的双向映射。

element()

使用休眠模式的场景的实体类

2 个答案: