发请求拿到的数据是扁平数组形式，怎么转换成el-tree树形式

问题遇到的现象和发生背景

发请求拿到的数据是一个数组

res:[
            {TENANT_ID_: "001",company_code: "00",company_name: "大坝1",id: "1",pid: "987"},
            {TENANT_ID_: "0010",company_code: "010",company_name: "大坝1-1",id: "1-1",pid: "987-1"},
            {TENANT_ID_: "00101",company_code: "010",company_name: "大坝1-1.1",id: "1-1.1",pid: "987-1.1"},
            {TENANT_ID_: "002",company_code: "00",company_name: "大坝2",id: "2",pid: "999"},
            {TENANT_ID_: "0020",company_code: "010",company_name: "大坝2-1",id: "2-1",pid: "999-1"},
            {TENANT_ID_: "00201",company_code: "010",company_name: "大坝2-1.1",id: "2-1.1",pid: "999-1.1"}
        ]

写的html 以及定义数据

<ht-tree 
                :tree-data="data" 
                :props="defaultProps"
                leaf-only = "true"
                include-half-checked = "true"
                @refresh="handleRefresh"   
                @node-click="handleNodeClick"
                >
            </ht-tree>

export default {
    data() {
      return {
          data:[]，
            defaultProps: {
            children: 'children',
            label: 'company_name'
        },
          }
      }
}

我想要达到的结果

想要element el-tree树的效果一样，可以附上完整代码

简单写了下，从案例上可以满足，给你个思路

let res = [
        { TENANT_ID_: "001", company_code: "00", company_name: "大坝1", id: "1", pid: "987" },
        { TENANT_ID_: "0010", company_code: "010", company_name: "大坝1-1", id: "1-1", pid: "987-1" },
        { TENANT_ID_: "00101", company_code: "010", company_name: "大坝1-1.1", id: "1-1.1", pid: "987-1.1" },
        { TENANT_ID_: "002", company_code: "00", company_name: "大坝2", id: "2", pid: "999" },
        { TENANT_ID_: "0020", company_code: "010", company_name: "大坝2-1", id: "2-1", pid: "999-1" },
        { TENANT_ID_: "00201", company_code: "010", company_name: "大坝2-1.1", id: "2-1.1", pid: "999-1.1" }
      ]

      let arr = []

      res.map(item => {
        item.children = []
        if (item.TENANT_ID_.length === 3) {
          arr.push(item)
        } else if (item.TENANT_ID_.length === 4) {
          let index = arr.findIndex(findChild => findChild.TENANT_ID_ === item.TENANT_ID_.substring(0, 3))
          arr[index].children.push(item)
        } else if (item.TENANT_ID_.length === 5) {
          let firstIndex = arr.findIndex(findChild => findChild.TENANT_ID_ === item.TENANT_ID_.substring(0, 3))
          let secondIndex = arr[firstIndex].children.findIndex(findChild => findChild.TENANT_ID_ === item.TENANT_ID_.substring(0, 4))
          arr[firstIndex].children[secondIndex].children.push(item)
        }
      })

  console.log('arr', arr)

function arrayToTree(items) {
  const result = [];   
  const itemMap = {};  // 
  for (const item of items) {
    const id = item.id;
    const pid = item.pid;

    if (!itemMap[id]) {
      itemMap[id] = {
        children: [],
      }
    }

    itemMap[id] = {
      ...item,
      children: itemMap[id]['children']
    }

    const treeItem =  itemMap[id];

    if (pid === 0) {
      result.push(treeItem);
    } else {
      if (!itemMap[pid]) {
        itemMap[pid] = {
          children: [],
        }
      }
      itemMap[pid].children.push(treeItem)
    }

  }
  return result;
}