使用 sequelize 的关联问题

Question

So, I´ve been trying to add a product_cart to my eCommerce app. I´m using Sequelize as ORM and MySQL. During development I figured that product_cart should be an intermediate table between users and products so I started to code using that logic. But after I made the many-to-many associations using belongsToMany(model.Product, {through: "product_cart", etc...}) the app started crashing every time a select query is made to the database. The error (the one associated with user) is:

"TypeError: include.model.getTableName is not a function" 

these are the models. First comes the User model:

module.exports = (sequelize, dataTypes) => {
  let alias = "User";
  let cols = {
    id: {
      autoIncrement : true,
      primaryKey : true,
      type : dataTypes.INTEGER,
    },
    firstName : {
      type : dataTypes.STRING,
    },
    lastName : {
      type : dataTypes.STRING,
    },
    email : {
      type : dataTypes.STRING,
    },
    password : {
      type : dataTypes.STRING,
    },
    isAdmin : {
      type : dataTypes.INTEGER,
    },
    avatar : {
      type : dataTypes.STRING,
    },
    address : {
      type : dataTypes.STRING,
    },
    phone : {
      type : dataTypes.STRING,
    }
  }

  let config = {
    tableName:"users",
    timestamps: false
  }

  let User = sequelize.define (alias, cols, config);

  User.associate = (models)=>{
    User.belongsToMany(models.Product,{
      as:"products",
      through: "product_cart",
      foreignKey: "id_user",
      otherKey: "product_id",
      timestamps : false
    });
  }
  return User;
}

Second the Product model:

module.exports  = (sequelize, dataTypes) => { 
  let alias = "Product";
  let cols = {
    id : {
      type : dataTypes.INTEGER,
      autoIncrement : true,
      primaryKey : true,
    },
    name : {
      type : dataTypes.STRING,
    },
    image : {
      type : dataTypes.STRING,
    },
    price : {
      type : dataTypes.FLOAT,
    },
    category_id : {
      type : dataTypes.INTEGER,
      foreignKey : true
    },
    description : {
      type : dataTypes.TEXT('medium'),
    },
    quantity : {
      type : dataTypes.INTEGER,
    }
  }

  let config = {
    tableName: "products",
    timestamps: false
  }
  let Product = sequelize.define (alias, cols, config);
    
  Product.associate = (models)=>{
    Product.belongsTo(models.Category, {
      as: "category",
      foreignKey: "category_id"
    });

    Product.belongsToMany(models.User,{
      as:"users",
      through: "product_cart",
      foreignKey: "product_id",
      otherKey: "id_user",
      timestamps : false
    });    
  }
  return Product;
}

and last is the product_cart:

module.exports  = (sequelize, dataTypes) => { 
  let alias = "ProductCart";
  let cols = {
    product_id : {
      type : dataTypes.INTEGER,
      foreignKey: true,
      primaryKey : true
    },
    user_id : {
      type : dataTypes.INTEGER,
      foreignKey : true,
      primaryKey : true
    },
    quantity : {
      type : dataTypes.INTEGER,
    },
  }
  let config = {
    tableName: "product_cart",
    timestamps: false
  }
  let ProductCart = sequelize.define (alias, cols, config);
 
  return ProductCart;
}

Answer 1

So, the solution to this problem, in my case was to change some attributes´s names because I was using them wrong. This problem is caused, commonly due to syntax errors. Hope this helps