MongoDB 的 $graphLookup 尝试获取树结构

使用 MongoDB 的 $graphLookup 尝试获取树结构

javascript
// 创建一个包含父子关系的集合
db.categories.insertMany([
  { _id: 1, name: "电子产品" },
  { _id: 2, name: "手机", parent: 1 },
  { _id: 3, name: "电视", parent: 1 },
  { _id: 4, name: "智能手机", parent: 2 },
  { _id: 5, name: "平板电脑", parent: 2 },
  { _id: 6, name: "曲面电视", parent: 3 },
]);
// 使用 $graphLookup 查询获取树形结构的数据
db.categories.aggregate([
  {
    $graphLookup: {
      from: "categories",
      startWith: "$_id",
      connectFromField: "_id",
      connectToField: "parent",
      as: "subcategories",
    },
  },
]);

javascript
// 创建一个包含组织结构信息的集合
db.organization.insertMany([
  { _id: 1, name: "公司", parent: null },
  { _id: 2, name: "技术部", parent: 1 },
  { _id: 3, name: "市场部", parent: 1 },
  { _id: 4, name: "开发组", parent: 2 },
  { _id: 5, name: "测试组", parent: 2 },
  { _id: 6, name: "销售组", parent: 3 },
]);
// 创建一个包含员工信息的集合
db.employees.insertMany([
  { name: "张三", departmentId: 4 },
  { name: "李四", departmentId: 4 },
  { name: "王五", departmentId: 5 },
  { name: "赵六", departmentId: 6 },
]);

javascript
// 使用 $graphLookup 查询获取组织结构的树形结构数据
db.organization.aggregate([
  {
    $graphLookup: {
      from: "organization",
      startWith: "$_id",
      connectFromField: "_id",
      connectToField: "parent",
      as: "suborganization",
    },
  },
  {
    $lookup: {
      from: "employees",
      localField: "_id",
      foreignField: "departmentId",
      as: "employees",
    },
  },
]);