Question

Database Structure

我只需要从表1中提取与表2中的数据相关的特定数据，例如：

让我们说“菜单”表中有两行-“比萨饼”和“薯条” 在“成分表”中，我有3行-“奶酪”，“土豆”，“酱”

“ Pizza”通过第三张表的外键连接到“ Cheese”和“ Sauce”，而“ Fries”连接到“ Potato”，现在我只想显示“ menu”表和“ Ingredients”中的数据互相连接的桌子。

例如：

Pizza-“奶酪”，“酱”

薯条-“土豆”

到目前为止，我只能列出两个表中的数据（所有数据），我无法选择显示哪些数据。

胸腺：

        <tr th:each="menu : ${menuList}">
        <td th:text="${menu.name}"></td>
        <td><a th:href="@{/foodDescription}" th:text="Description">Description</a></td>
        <td th:each="ing : ${ingredientList}">
            <ul>
                <li th:text = ${ing.ingredientName}></li>
                <!-- Here I only want to display ingredientName and description which 
                are connected to the specific ${menu.name} -->
            </ul>
        </td>
    </tr>

控制器：

    @Controller
    public class MyController{

    @Autowired
    MenuRepository menuRepository;

    @Autowired
    IngredientRepository ingredientRepository;

    @GetMapping("/hello")
    private String hello(){
        return "hello-page";
    }

    @GetMapping("/recipeList")
    public String listPage(Model model){
        model.addAttribute("menuList",menuRepository.findAll());
        model.addAttribute("ingredientList", ingredientRepository.findAll());
        return "list-page";
    }

Menu.java：

@Entity
@Table(name = "menu")
public class Menu {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int id;

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

    // Mapping To second table
    @OneToMany(cascade = CascadeType.ALL)
    @JoinTable(name = "menu_ingredient",
               joinColumns = @JoinColumn(name = "menu_id"),
               inverseJoinColumns = @JoinColumn(name = "ingredient_id"))
    private List<Ingredients> ingredient = new ArrayList<>();
// Constructor/Getter/Setter/ToString

Ingredient.java：

@Entity
@Table(name = "ingredients")
public class Ingredients {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int id;

    @Column(name = "ingredient")
    private String ingredientName;

    @Column(name = "description")
    private String ingredientDescription;

Answer 1

由于Menu与Ingredients有关联，因此它将包含链接的成分。您无需分别获取Ingredients。

<tr th:each="menu : ${menuList}">
    <td th:text="${menu.name}"></td>
    <td><a th:href="@{/foodDescription}" th:text="Description">Description</a></td>
    <td th:each="ing : ${menu.ingredient}"> <!-- I have only modified here -->
        <ul>
            <li th:text = ${ing.ingredientName}></li>
        </ul>
    </td>

从mysql数据库中提取特定数据到thymeleaf

1 个答案: