查询多级商品分类怎么依次显示到页面上？(2/3)

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CREATE TABLE `admin_menu` (
  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT COMMENT '自增id',
  `name` varchar(64) NOT NULL COMMENT '菜单名',
  `parent_id` bigint(3) NOT NULL DEFAULT 0 COMMENT '父菜单的id, 如果是父菜单这个值为0',
  `url` varchar(500) NOT NULL DEFAULT '' COMMENT '菜单的链接',
  `icon` varchar(100) NOT NULL DEFAULT '' COMMENT '图标',
  `menu_index` bigint(3) NOT NULL DEFAULT 0 COMMENT '展示的顺序',
  `create_time` datetime NOT NULL COMMENT '创建时间',
  `update_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '最后更新时间',
  PRIMARY KEY (`id`),
  KEY `uq_id` (`id`),
  KEY `uq_parent_id` (`parent_id`)
) ENGINE=InnoDB AUTO_INCREMENT=0 DEFAULT CHARSET=utf8 COMMENT='管理后台的菜单';

其中parentId 跟你的typeParent类似, 记录上一级的id

AdminMenu (Model):

public class AdminMenu implements Serializable {

    private static final long serialVersionUID = -6535315608269812875L;
    private int id;
    private String name;
    private int parentId;
    private String url;
    private String icon;
    private int menuIndex;
    private Date createTime;
    private Date updateTime;
    private List subMenus;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

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

    public int getParentId() {
        return parentId;
    }

    public void setParentId(int parentId) {
        this.parentId = parentId;
    }

    public String getUrl() {
        return url;
    }

    public void setUrl(String url) {
        this.url = url;
    }

    public String getIcon() {
        return icon;
    }

    public void setIcon(String icon) {
        this.icon = icon;
    }

    public int getMenuIndex() {
        return menuIndex;
    }

    public void setMenuIndex(int menuIndex) {
        this.menuIndex = menuIndex;
    }

    public Date getCreateTime() {
        return createTime;
    }

    public void setCreateTime(Date createTime) {
        this.createTime = createTime;
    }

    public Date getUpdateTime() {
        return updateTime;
    }

    public void setUpdateTime(Date updateTime) {
        this.updateTime = updateTime;
    }

    public List getSubMenus() {
        return subMenus;
    }

    public void setSubMenus(List subMenus) {
        this.subMenus = subMenus;
    }

    @Override
    public String toString() {
        return JsonUtil.toJson(this);
    }
}

Model的属性跟表结构一一对应, 最下面多了一个subMenu, 里面就是AdminMenu

下面是admin_menu.xml中的内容

查询SQL:

    SELECT
        id, name, parent_id, url, icon, menu_index, create_time, update_time
    FROM
      admin_menu
    WHERE parent_id=0
    ORDER BY menu_index

这里返回的就是adminMenuResult结果集:

其中这一行是最重要的

这里用selectSubMenus来进行了另一个查询, 查询的参数为id, 把查询出来的结果放在Model中的subMenus属性中.

selectSubMenus查询SQL: