如何建立客户、产品、类别和订单之间的关系。以及如何实现表单标签

Question

我有产品，客户，订单实体。我需要找到关系，以便在订单实体上收集所有这些实体，该实体将保存客户信息和产品信息。

在这个Html页面中，我需要创建链接这个将添加到订单实体中的信息，这样当我创建另一个页面以获取所有订单时，我可以查看用户插入的信息的所有订单。

类别实体类

@Entity
@Data
public class Categories {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long categories_id;

    private String categoryName;

客户实体类

@Entity
@Data
@Table(name="customers")
public class Customers {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long customer_id;
    private String customer_fName;
    private String customer_lName;
    private String customer_email;
    private String customer_address;
    private String customer_state;
    private String customer_phone;
    private String customer_zipCode;

    @OneToMany(targetEntity = Orders.class,cascade = CascadeType.ALL)
    @JoinColumn(name = "customer_order_fk",referencedColumnName = "customer_id")//means will be a fk in orders table
    private List<Orders> orders;

    public Customers()
    {
        super();
    }

    public Customers(String customer_fName, String customer_lName, String customer_email, String customer_phone,String customer_address ,String customer_state,String customer_zipCode) {
        this.customer_zipCode = customer_zipCode;
        this.customer_phone = customer_phone;
        this.customer_state = customer_state;
        this.customer_address = customer_address;
        this.customer_fName = customer_fName;
        this.customer_lName = customer_lName;
        this.customer_email = customer_email;
    }

产品实体类

@Entity
@Table(name = "Products")
@Data
public class Products {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private long product_id;

    private String product_name;

    private BigDecimal product_price;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "categories_id",nullable = false) //the name of the column in the other class and that name will be a column in the class
    private Categories product_category;

    private String product_quantity;

    private String product_Section;

    private String product_ExpDate;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "")
    private Customers customer;

    @ManyToOne
    @JoinColumn(name = "order_order_id")
    private Orders order;

    public Products()
    {
        super();
    }

    public Products(String product_name, BigDecimal product_price,String product_quantity, String product_Section,String product_ExpDate) {
        this.product_name = product_name;
        this.product_price = product_price;
        this.product_quantity = product_quantity;
        this.product_Section = product_Section;
        this.product_ExpDate = product_ExpDate;
    }

订单控制器类

@Controller

公共类订单控制器 {

@Autowired
private OrdersService ordersService;

@Autowired
private CustomerService customerService;

@Autowired
private ShoppingCartImpService shoppingCartImpService;

@ModelAttribute("order")
public Orders orders()
{
    return new Orders();
}

@GetMapping("/orders/getAllorders")
public String listAllOrders(Model model)
{
    model.addAttribute("order",ordersService.getAllOrders());
    return "showTransactions";
}

@GetMapping("/orders/delete/{id}")
public String deleteOrderById(@PathVariable Long id)
{
    ordersService.deleteOrder(id);
    return "redirect:/orders/getAllorders";
}

@PostMapping("/orders/save/order")
public String saveOrders(@ModelAttribute("order") Orders orders)
{
    ordersService.saveOrders(orders);

    return "redirect:/orders/getAllorders";
}

@GetMapping("/showTransaction/customer/{id}") //this to list all items choosen by a specific customer
public String showShoppingCart(Model model,@PathVariable Long id)
{
    Customers customer = customerService.getCustomerById(id);

    List<CartItem> listCartItems = shoppingCartImpService.listCartItems(customer);//customer.id

    model.addAttribute("CartItems",listCartItems);

    return "showTransactions";
}

制作账单页面

<h4 class="mb-3">Customer Information</h4>
            <form class="needs-validation" novalidate="" th:action="@{/orders/save/order}" method="post" th:object="${order}" id="form">
                <div class="row g-3">
                    <div class="col-sm-6">
                        <label for="firstName" class="form-label">First name</label>
                        <input type="text" class="form-control" id="firstName"  placeholder="" value="" required="" autofocus th:field="*{customer_fname}">
                        <div class="invalid-feedback">
                            Valid first name is required.
                        </div>
                    </div>


                    <div class="col-sm-6">
                        <label for="lastName" class="form-label">Last name</label>
                        <input type="text" class="form-control" id="lastName" placeholder="" value="" required="" autofocus th:field="*{customer_lname}">
                        <div class="invalid-feedback">
                            Valid last name is required.
                        </div>
                    </div>


                    <div class="col-12">
                        <br>
                        <label for="address" class="form-label">Address</label>
                        <input type="text" class="form-control" id="address" placeholder="Address" required="" autofocus th:field="*{customer_address}">
                        <div class="invalid-feedback">
                            Please enter your shipping address.
                        </div>
                    </div>

                </div>

                <br>
                <hr class="my-4">

                <!--product info-->

                <div class="row g-3">
                    <div class="col-12">
                        <h4 class="mb-3">Select A Product</h4>
                        <br>

                        <label th:for="category"> Category : </label>
                        <select class="form-control form-control-sm" id="category" name="category" autofocus>
                            <option value="">Select Category</option>
                            <option th:each = "product: ${product}"
                                    th:text="${product.product_category}"
                            >
                            </option>
                        </select>

                        <br>
                        <label th:for="product"> Product Name : </label>
                        <select class="form-control form-control-sm" id="product" name="product" autofocus>
                            <option value="">Select Product</option>
                            <option th:each = "product: ${product}"
                                    th:text="${product.product_name}"
                            >
                            </option>
                        </select>

                        <br>
                        <label th:for="product_price"> Product Price : </label>
                        <input class="form-control form-control-sm" id="product_price" name="product_price" disabled >

                        <br>
                        <label th:for="roles"> Product Quantity : </label>
                        <input class="form-control form-control-sm" id="product_Qty" name="product_Qty" autofocus>

                        <br>

                        <button class="w-5 btn btn-primary " type="submit" id="add_submit" >Add </button>

                    </div>
                </div>
                <br>
                <hr class="my-4">

                <!-- TABLE -->

                <table class = "table table-striped table-bordered" id="show">
                    <thead class = "table-white">
                    <tr>
                        <th> Category </th>
                        <th> Product Name </th>
                        <th> Product Price </th>
                        <th> Product Quantity </th>
                        <th> Total </th>
                        <th> Edit </th>
                        <th> Delete </th>
                    </tr>
                    </thead>

                    <tbody>

                    <tr th:each = "product: ${product}"> <!-- this attribute to list up products  -->

                        <td th:text="${product.product_category}" ></td>
                        <td th:text="${product.product_name}"></td>
                        <td th:text="${product.product_price}"></td>
                        <td th:text="${product.product_quantity}" ></td>
                        <td th:text="${product.product_quantity}" ></td>

                        <td> <center> <a th:href="@{/products/edit/{id}(id=${product.product_id})}" style="color: green"> Edit </a> </center> </td>

                        <td> <center> <a th:href="@{/products/delete_product/{id}(id=${product.product_id}) }" style="color: red"> Delete </a> </center> </td>

                    </tr>

                    </tbody>

                </table>




                <h4 class="mb-3"></h4>

                <br>

                <div class="row g-3">
                    <div class="col-12">
                        <h5 class="mb-3" id="total_bill"> Total: $</h5>
                    </div>
                </div>

                <br>

                <button class="w-100 btn btn-primary btn-lg" type="submit">Generate Bill</button>
            </form>

Answer 1

您可以在单独的数据库表中管理客户和订单之间的映射，您可以将客户实体中的订单映射为：

    @OneToMany(targetEntity = Orders.class,cascade = CascadeType.ALL)
    @JoinTable(name = "customers_orders", 
               joinColumns = @JoinColumn(name = "customer_id"),
               inverseJoinColumns = @JoinColumn(name = "order_id"))
    private List<Orders> orders;

如果要持久化或只想获取与客户相关的订单，则必须管理CascadeType。