我正在尝试使用 Sequelize 在 Node JS 中为 n:m 关联构建模型。
下面的图像显示了我试图在后端映射的内容:

使用官方文档,我定义的模型如下:

let Dashboards = sequelize.define('Dashboards', {
    name: DataType.STRING(30),
    category: DataType.TINYINT(2)
}, {
    freezeTableName: true,
    timestamps: false,
    tableName: 'dashboards'
});

Dashboards.associate = function (models) {
    Dashboards.belongsToMany(models.Charts, {
        through: {
            unique: false,
            model: models.DashboardCharts
        },
        foreignKey: 'dashboardId'
    });
};

let Charts = sequelize.define('Charts', {
    type: DataType.INTEGER(5),
    title: DataType.STRING(30),
}, {
    freezeTableName: true,
    timestamps: false,
    tableName: 'charts'
});

Charts.associate = function (models) {
    Charts.belongsToMany(models.Dashboards, {
        through: {
            unique: false,
            model: models.DashboardCharts,
        },
        foreignKey: 'chartId'
    });
};
let DashboardCharts = sequelize.define('DashboardCharts', {
    title: {
        type: DataType.STRING(30)
    },
    color: {
        type: DataType.STRING(7)
    }
}, {
freezeTableName: true,
    timestamps: false,
    tableName: 'dashboard_charts'
});

现在,如果使用 DashboardCharts,我尝试以这种方式将表与 Dashboards 连接起来:
DashboardCharts.findAll({
    include: [
        {
            model: Dashboard,
            required: true,
        }
    ]
})

我收到此错误: SequelizeEagerLoadingError: Dashboards is not associated to DashboardCharts!
我究竟做错了什么?感谢任何可以帮助我的人!

最佳答案

我找到了解决方案:我做关联是错误的。使用当前配置,我只能要求 Dashboard 的图表,反之亦然。正确的解决方案是从连接表中设置belongsTo,如下所示:

let Dashboards = sequelize.define('Dashboards', {
    name: DataType.STRING(30),
    category: DataType.TINYINT(2)
}, {
    freezeTableName: true,
    timestamps: false,
    tableName: 'dashboards'
});

let Charts = sequelize.define('Charts', {
    type: DataType.INTEGER(5),
    title: DataType.STRING(30),
}, {
    freezeTableName: true,
    timestamps: false,
    tableName: 'charts'
});


let DashboardCharts = sequelize.define('DashboardCharts', {
    dashboard_id: {
        type: DataType.INTEGER(5),
        primaryKey: true
    },
    chart_id: {
        type: DataType.INTEGER(5),
        primaryKey: true
    },
    title: {
        type: DataType.STRING(30)
    },
    color: {
        type: DataType.STRING(7)
    }
}, {
    freezeTableName: true,
    timestamps: false,
    tableName: 'dashboard_charts'
});

DashboardCharts.associate = function (models) {
    DashboardCharts.belongsTo(models.Dashboards, {
        foreignKey: 'dashboard_id',
        sourceKey: models.Dashboards.id
    });

    DashboardCharts.belongsTo(models.Charts, {
        foreignKey: 'chart_id',
        sourceKey: models.Charts.id
    });
};

关于mysql - Sequelize n :m association join table with attributes,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/52371188/

10-11 01:20