本文連接 https://www.cnblogs.com/aknife/p/11709255.html

一.頁面樣式

二.資料庫

 三.前端頁面代碼

 1 <template>
 2 
 3   <el-tree :props="props"
 4            :load="loadNode"
 5            lazy
 6            show-checkbox>
 7   </el-tree>
 8 
 9 </template>
10 <script>
11 export default {
12   data () {
13     return {
14       props: {
15         label: 'name',
16         children: 'zones',
17         isLeaf: 'leaf',
18 
19       },
20     };
21   },
22   methods: {
23     loadNode (node, resolve) {
24       //如果展開第一級節點，從後臺載入一級節點列表
25       if (node.level == 0) {
26         this.loadfirstnode(resolve);
27       }
28       //如果展開其他級節點，動態從後臺載入下一級節點列表
29       if (node.level >= 1) {
30         this.loadchildnode(node, resolve);
31       }
32     },
33     //載入第一級節點
34     loadfirstnode (resolve) {
35 
36       this.api({
37         url: "/test/tree",
38         method: "post",
39 
40       }).then(data => {
41         console.log(data);
42         //this.data = data.list;
43         return resolve(data.list);
44 
45       })
46     },
55     //載入節點的子節點集合
56     loadchildnode (node, resolve) {
57       this.api({
58         url: "/test/tree2",
59         method: "post",
60         params: {
61           id: node.data.id
62         }
63       }).then(data => {
64         console.log(data);
65         //this.defaultProps.children = data.list;
66         return resolve(data.list);
67 
68       })
69     }
70 
71   }
72 
73 }
74 </script>

controller層

    @PostMapping("/tree")
    public JSONObject tree( ) {return userService.tree();
    }

    @PostMapping("/tree2")
    public JSONObject tree(@RequestParam Map<String, Object> user) {return userService.tree2(user);
    }

service層

    /**
     * 樹
     */
    JSONObject tree();
    
    /**
     * 樹
     */
    JSONObject tree2(Map<String, Object> user);

serviceImpl層

    @Override
    public JSONObject tree() {
        List<JSONObject> list=userDao.tree();
        System.out.println(list);
        return CommonUtil.successPage(list);
    }
    
    @Override
    public JSONObject tree2(Map<String, Object> user) {
        int codept=Integer.parseInt(user.get("id").toString()) ;
        List<JSONObject> list=userDao.tree2(codept);
        return CommonUtil.successPage(list);
    }

dao層

    /**
     * 樹
     */
    List<JSONObject> tree();
    List<JSONObject> tree2(@Param("codept")int codept);

mapper層

    <select id="tree" resultType="com.alibaba.fastjson.JSONObject">
     SELECT [id]
      ,[codept]
      ,[name]
  FROM [dbo].[Dept] WHERE codept ='0'
    </select>

   <select id="tree2" resultType="com.alibaba.fastjson.JSONObject">
     SELECT [id]
      ,[codept]
      ,[name]
  FROM [dbo].[Dept] WHERE codept =#{codept}
    </select>

本文連接https://www.cnblogs.com/aknife/p/11709255.html