Sequelize - 仅返回关系答案

【问题标题】：Sequelize - Return only relationshipsSequelize - 仅返回关系
【发布时间】：2021-05-14 21:04:31
【问题描述】：

我有一个问题，我需要从我的flows 关系中返回一个数组。如何获取包含所有公司流量列表的数组？

我的模型和迁移是正确的，我只是不知道如何让查询只返回flows。

公司模式

module.exports = (sequelize) => {
    const company = sequelize.define('company', {
        id: {
            allowNull: false,
            autoIncrement: true,
            primaryKey: true,
            type: DataTypes.INTEGER
        },
        uuid: {
            type: DataTypes.UUID,
            defaultValue: DataTypes.UUIDV4
        },
        name: {
            type: DataTypes.STRING,
            allowNull: false
        }
    })

    company.hasMany(sequelize.models.flow, {foreignKey: 'company_id', as: 'flows'})
}

流动模型

module.exports = (sequelize) => {
    const flow = sequelize.define('flow', {
        id: {
            allowNull: false,
            autoIncrement: true,
            primaryKey: true,
            type: DataTypes.INTEGER
        },
        company_id: {
            allowNull: false,
            type: DataTypes.INTEGER
        },
        uuid: {
            type: DataTypes.UUID,
            defaultValue: DataTypes.UUIDV4
        },
        name: {
            type: DataTypes.STRING,
            allowNull: false
        },
        description: {
            type: DataTypes.TEXT
        }
    })

    flow.belongsTo(sequelize.models.company, {foreignKey: 'company_id', as: 'company'})
}

查询

const companies = await ORM.models.company
    .findAll({
        include: [{
            model: ORM.models.flow,
            as: 'flows'
        }]
    })

此查询返回如下：

[
    {
        "id": 1,
        "uuid": "f0c1a5e1-c54c-4083-8284-5a9b272e8ba1",
        "name": "Company 1",
        "created_at": "2021-02-11T05:47:55.830Z",
        "updated_at": "2021-02-11T05:47:55.830Z",
        "flows": [
            {
                "id": 1,
                "company_id": 1,
                "uuid": "768262d2-88b7-4e0f-81e8-30d7253aae65",
                "name": "Flow 1",
                "description": null,
                "created_at": "2021-02-11T05:48:10.211Z",
                "updated_at": "2021-02-11T05:48:10.211Z",
                "companyId": 1
            }
        ]
    },
    {
        "id": 2,
        "uuid": "3dea2541-a505-4f0c-a356-f1a2d449d050",
        "name": "Company 1",
        "created_at": "2021-02-11T05:48:11.872Z",
        "updated_at": "2021-02-11T05:48:11.872Z",
        "flows": [
            {
                "id": 2,
                "company_id": 2,
                "uuid": "3e66e8e6-3754-41e5-93ca-6e8ed49e2025",
                "name": "Flow 2",
                "description": null,
                "created_at": "2021-02-11T05:48:20.743Z",
                "updated_at": "2021-02-11T05:48:20.743Z",
                "companyId": 2
            }
        ]
    }
]

我需要这样返回：

[
   {
      "id":1,
      "company_id":1,
      "uuid":"768262d2-88b7-4e0f-81e8-30d7253aae65",
      "name":"Flow 1",
      "description":null,
      "created_at":"2021-02-11T05:48:10.211Z",
      "updated_at":"2021-02-11T05:48:10.211Z",
      "companyId":1
   },
   {
      "id":2,
      "company_id":2,
      "uuid":"3e66e8e6-3754-41e5-93ca-6e8ed49e2025",
      "name":"Flow 2",
      "description":null,
      "created_at":"2021-02-11T05:48:20.743Z",
      "updated_at":"2021-02-11T05:48:20.743Z",
      "companyId":2
   }
]

【问题讨论】：

显示模型和关联定义
@Anatoly 更新

标签： node.js sequelize.js

【解决方案1】：

如果你只想要流量相关数据，为什么要获取公司相关数据，其中包含流量？也许，您只能获取流数据。

const flows = await ORM.models.flow
.findAll({
   where: ....,
   ..........
});

如果您仍然想显示特定公司的流程而不显示公司模型的任何属性，请执行以下操作：

const companies = await ORM.models.company
.findAll({
    attributes: [], //empty 
    include: [{
        model: ORM.models.flow,
        as: 'flows'
    }]
});

【讨论】：