sequelize.js - Sequelize findOne 返回 null 然后模型为空

Question

我有一个函数，它必须返回包含域事件的配置。

async function getConfig(configId, country) {
    return await db.config.findOne({
        where: { id: configId },
        include: [
            {
                model: db.domain,
                attributes: ['id', 'domain'],
                where: {
                    isActive: true,
                },
            },
        ],
    });
}

但是我收到错误 default - TypeError: Cannot read property 'dataValues' of undefined 因为我的表 domain 是空的但我想得到结果

    "result": {
        "id": 4,
        "country": "US",
        "domains": []
    }

我该怎么做？
配置模型

const { Model } = require('sequelize');

module.exports = (sequelize, DataTypes) => {
    class Config extends Model {
        /**
         * Helper method for defining associations.
         * This method is not a part of DataTypes lifecycle.
         * The `models/index` file will call this method automatically.
         */
        static associate(models) {
            Config.hasMany(models.domain, {
                foreignKey: 'configId',
                onDelete: 'CASCADE',
            });
        }
    }

    Config.init(
        {
            id: {
                allowNull: false,
                autoIncrement: true,
                primaryKey: true,
                type: DataTypes.INTEGER,
            },
            country: {
                type: DataTypes.STRING,
                allowNull: false,
            },
        },
        {
            sequelize,
            tableName: 'configs',
            modelName: 'config',
            timestamps: false,
        },
    );
    return Config;
};

领域模型

const { Model } = require('sequelize');

module.exports = (sequelize, DataTypes) => {
    class Domain extends Model {
        /**
         * Helper method for defining associations.
         * This method is not a part of DataTypes lifecycle.
         * The `models/index` file will call this method automatically.
         */
        static associate(models) {
            Domain.belongsTo(models.config, {
                foreignKey: 'configId',
            });
        }
    }

    Domain.init(
        {
            id: {
                allowNull: false,
                autoIncrement: true,
                primaryKey: true,
                type: DataTypes.INTEGER,
            },
            domain: {
                type: DataTypes.STRING,
                allowNull: false,
            },
            isActive: {
                type: DataTypes.BOOLEAN,
                allowNull: false,
                defaultValue: false,
            },
        },
        {
            sequelize,
            tableName: 'domains',
            modelName: 'domain',
            timestamps: false,
        },
    );
    return Domain;
};

Answer 1

您只需要像这样指示 required: false 选项:

return await db.config.findOne({
        where: { id: configId },
        include: [
            {
                required: false,
                model: db.domain,
                attributes: ['id', 'domain'],
                where: {
                    isActive: true,
                },
            },
        ],
    });

这样你就对 Sequelize 说你希望获得主模型实例，而不管关联模型中的条件如何。
如果您熟悉 SQL，则意味着将 INNER JOIN 转换为 LEFT OUTER JOIN 。