sequelize [erro]{ this.name}.hasMany 中的模型关联使用不是 Sequelize.Model 子类的东西调用答案

【问题标题】：Model association in sequelize [erro]{ this.name}.hasMany called with something that's not a subclass of Sequelize.Modelsequelize [erro]{ this.name}.hasMany 中的模型关联使用不是 Sequelize.Model 子类的东西调用
【发布时间】：2020-03-07 12:04:21
【问题描述】：

我正在尝试创建一个项目并使用node.js + sequelize，该项目有两个模型Fator和Sub_fator。它们有一个关联 1:N，但是在创建 fator 时，返回了一个错误：

错误：Fator.hasMany 调用的东西不是 Sequelize.Model 的子类

有解决错误的建议吗？

模型因子

'use strict';
const Sub_Fator = require('./sub_fator');

module.exports = (sequelize, DataTypes) => {
  const Fator = sequelize.define('Fator', {
    descricao: DataTypes.STRING
  }, {});
  Fator.associate = function(models) {
      Fator.hasMany(Sub_Fator, {
      foreignKey: 'fatorId',
      as: 'fatores'
    });
  };
  return Fator;
};

模型Sub_fator

'use strict';
const Fator = require('./fator');

module.exports = (sequelize, DataTypes) => {
  const Sub_Fator = sequelize.define('Sub_Fator', {
    fatorId: DataTypes.INTEGER,
    descricao: DataTypes.STRING
  }, {});
  Sub_Fator.associate = function(models) {
    Sub_Fator.belongsTo(Fator, {
      foreignKey: 'fatorId',
      as: 'fatores'
    });
  };
  return Sub_Fator;
};

【问题讨论】：

标签： node.js postgresql orm sequelize.js

【解决方案1】：

//Removed this import because is not an object of Model it's a definition
module.exports = (sequelize, DataTypes) => {
  const Fator = sequelize.define('Fator', {
    descricao: DataTypes.STRING
  }, {});
  Fator.associate = function(models) {
      Fator.hasMany(models.Sub_Fator, {//Change to this instead of Sub_Fator
        foreignKey: 'fatorId',
        as: 'fatores'
    });
  };
  return Fator;
};

原因是因为你在这里定义了模型，但是在你的 models/index.js 或类似的东西中你必须导入它来生成一个对象模型，这只是一个模型定义，它不是 Sequelize 的子类.模型。

PS：如果您在项目中生成了 sequelize，您的索引应该是这样的：

'use strict';

var fs        = require('fs');
var path      = require('path');
var Sequelize = require('sequelize');
var basename  = path.basename(module.filename);
var env       = process.env.NODE_ENV || 'development';
var config    = require(__dirname + '/../config/server-config.json')[env];
var db        = {};

if (config.use_env_variable) {
  var sequelize = new Sequelize(process.env[config.use_env_variable]);
} else {
  var sequelize = new Sequelize(config.database, config.username, config.password, config);
}

fs
  .readdirSync(__dirname)
  .filter(function(file) {
    return (file.indexOf('.') !== 0) && (file !== basename) && (file.slice(-3) === '.js');
  })
  .forEach(function(file) {
    var model = sequelize['import'](path.join(__dirname, file));
    db[model.name] = model;
  });

Object.keys(db).forEach(function(modelName) {
  if (db[modelName].associate) {
    db[modelName].associate(db);
  }
});

db.sequelize = sequelize;
db.Sequelize = Sequelize;

module.exports = db;

【讨论】：