nest js 中 Sequelize 的嵌套层次结构 (sequelize-hierarchy)

Question

我一直在尝试创建一个带有自连接的树表（mssql，sequelize）。

\+----+--------------+--------+
| id |     name     | parent |
\+----+--------------+--------+
|  1 | ABC          | null   |
|  2 | DEF          | null   |
|  3 | GHI          | 2      |
|  4 | JKL          | 3      |
|  5 | MNO          | 4      |
\+----+--------------+--------+

我需要以下结果。请注意，深度是无限的。

[
    {
        "id": 1,
        "name": "ABC",
        "children": null
    },
    {
        "id": 2,
        "name": "DEF",
        "children": [
                      {
                        "id": 3,
                        "name": "GHI",
                        "children": [
                                  {
                                  "id": 4,
                                  "name": "JKL",
                                  "children": [ {
                                     "id": 5,
                                     "name": "MNO",
                                     "children": null
                                },]
                      },
]
                      },
                     
                    ]
    }
]

下面是我的模型

@Table()
export class AccHead extends Model {
  @Column({
    type: DataType.BIGINT,
    primaryKey: true,
    autoIncrement: true,
  })
  id: number;
  name: string;

@ForeignKey(() => AccHead)
  @Column({
    type: DataType.BIGINT,
    onDelete: 'NO ACTION',
  })
  parentId: number;

@BelongsTo(() => AccHead, { foreignKey: 'parentId' })
  parent: AccHead;
  @HasMany(() => AccHead, { foreignKey: 'parentId' })
  children: AccHead[];
}

我尝试了下面的查询，但它只限于我包含模型的级别，我想递归地包含子项： （原表超过150k+条记录，需要优化查询）

const hierarchicalData = await AccHead.findAll({
        where: {
          parentId: null, // Retrieve top-level categories
        },

        include: [
          {
            model: AccHead,
            as: 'children',
            where: {
              parentId: { [Op.ne]: null }, 
            },
            include: [
              {
                model: AccHead,
                as: 'children', 
                include: [
                  {
                    model: AccHead,
                    as: 'children', 
                   
                  },
                ],
              },
            ],
          },
        ],
      });

我找到的最佳解决方案之一是
sequelize-hierarchy Documentation 这正是我所需要的。它有自己的函数来处理树操作。

const Folder = sequelize.define('folder', { name: Sequelize.STRING });
Folder.isHierarchy();

或者

const Folder = sequelize.define('folder', {
  name: Sequelize.STRING
}, {
  hierarchy: true
});

但是我无法在 Nest Js 中实现它，因为该文档是用于 Node.js 中的续集。 有人可以帮我在 Nest js 中做同样的事情，或者任何其他更好的方法吗？

Answer 1

    import {
    Table,
    Column,
    Model,
    DataType,
    ForeignKey,
    BelongsTo,
} from 'sequelize-typescript';
import { Hierarchy } from 'sequelize-hierarchy';

@Table
@Hierarchy({
    foreignKey: 'parentId',
    levelFieldName: 'level',
    structure: 'tree',
})
export class Category extends Model<Category> {
    @Column({
        type: DataType.STRING,
        allowNull: false,
    })
    name: string;

    @Column({
        type: DataType.INTEGER,
        allowNull: true,
    })
    parentId: number;

    @BelongsTo(() => Category)
    parent: Category;
}

Try This, Answer by Chat Gpt