属于关联使用联想似乎并没有工作

Question

我在我的应用程序两个“模式”被分流到不同的文件：

ApplicationSession.model.js

module.exports = function(sequelize, DataTypes) { 

    const { INTEGER, DATE } = DataTypes; 

    var ApplicationSession = sequelize.define("applicationSession", { 
     sessionStart: DATE, 
     sessionEnd: DATE 
    }, { 
     associate: (models) => { 
      ApplicationSession.belongsTo(models.User, { 
       foreignKey: 'userId', 
       as: 'User', 
      }); 
     } 
    }); 

    return ApplicationSession; 
}; 

User.model.js

module.exports = function(sequelize, DataTypes) { 

    const { STRING, INTEGER, DATE } = DataTypes; 

    var User = sequelize.define("user", { 
     name: STRING 
    }, { 
     associate: (models) => { 
      User.hasMany(models.ApplicationSession); 
     } 
    }); 

    return User; 
}; 

当保存表（DROPING/RECREATING）force: true和手动丢弃仅用于理智时，永远不会为用户创建一个字段。

这里是我如何我的加载不同型号

import fs from 'fs'; 
import path from 'path'; 
import sequelize from '../connection'; 
var exports = {}; 

fs.readdirSync(__dirname).forEach(fileName => { 
    if(~fileName.indexOf('.model.js')) { 
     const subname = fileName.replace('.model.js', ''); 

     const model = sequelize.import(path.join(__dirname, fileName)); 
     exports[subname] = model; 
    } 

}); 

export default exports; 

当所有的车型在一个单一的文件中声明，我可以使用X.belongsTo(Y)没有任何问题，所以我想我会尝试加入这我sequelize.import下称

exports['ApplicationSession'].belongsTo(exports['User'], { as: 'User', foreignKey: 'userId' }); 
    exports['User'].hasMany(exports['ApplicationSession']); 

然而，这产生了不同的错误：

/node_modules/sequelize/lib/associations/mixin.js:96 
     throw new Error(this.name + '.' + Utils.lowercaseFirst(Type.toString()) + ' called with something that\'s not an instance of Sequelize.Model'); 
    ^

Error: applicationSession.function BelongsTo(source, target, options) 

我该怎么做才能使人际关系发挥作用？

Answer 1

您需要在模型加载模块中添加一件以使关联工作。

fs.readdirSync(__dirname).forEach(fileName => { 
    if(~fileName.indexOf('.model.js')) { 
     const subname = fileName.replace('.model.js', ''); 
     const model = sequelize.import(path.join(__dirname, fileName)); 
     exports[subname] = model; 
    } 
}); 

// You need to check for every model if it has `associate` class method 
// and execute it 
Object.keys(exports).forEach(function(modelName) { 
    if ("associate" in exports[modelName]) { 
    exports[modelName].associate(db); 
    } 
}); 

我还在代码中看到了另一个错误。在您的模型associate中定义的类方法应该包含classMethods属性。

它应该是这样的：

var ApplicationSession = sequelize.define("applicationSession", { 
    sessionStart: DATE, 
    sessionEnd: DATE 
}, { 
    // Add this 
    classMethods: { 
     associate: (models) => { 
      ApplicationSession.belongsTo(models.User, { 
       foreignKey: 'userId', 
       as: 'User', 
      }); 
     } 
    } 
}); 

您可以通过sequelize在GitHub下面的例子。