Sequelize Eager Loading Error when including related model - postgresql

Question

I'm using Sequelize to make this request:
return Expense.findAll({
include: [{
model: ExpenseCategory
}],
})
.then(expenses => res.status(200).send(expenses))
.catch(error => res.status(500).send({ error: error }));
and I'm getting this error:
SequelizeEagerLoadingError
I can't seem to find my error.
This are my migrations for the three models (User, Expense, ExpenseCategory):
queryInterface.createTable('Users', {
id: {
allowNull: false,
autoIncrement: true,
primaryKey: true,
type: Sequelize.INTEGER
},
email: {
allowNull: false,
type: Sequelize.STRING,
unique: true
},
passhash: {
allowNull: false,
type: Sequelize.STRING
},
currency: {
type: Sequelize.STRING,
defualt: 'lev'
},
createdAt: {
allowNull: false,
type: Sequelize.DATE
},
updatedAt: {
allowNull: false,
type: Sequelize.DATE
}
});
queryInterface.createTable('Expenses', {
id: {
allowNull: false,
autoIncrement: true,
primaryKey: true,
type: Sequelize.INTEGER
},
value: {
allowNull: false,
type: Sequelize.FLOAT
},
text: {
type: Sequelize.STRING
},
expenseCategoryId: {
allowNull: false,
type: Sequelize.INTEGER,
references: {
model: 'ExpenseCategories',
key: 'id'
},
onDelete: 'cascade'
},
userId: {
allowNull: false,
type: Sequelize.INTEGER,
references: {
model: 'Users',
key: 'id'
},
onDelete: 'cascade'
},
createdAt: {
allowNull: false,
type: Sequelize.DATE
},
updatedAt: {
allowNull: false,
type: Sequelize.DATE
}
});
queryInterface.createTable('ExpenseCategories', {
id: {
allowNull: false,
autoIncrement: true,
primaryKey: true,
type: Sequelize.INTEGER
},
category: {
allowNull: false,
type: Sequelize.STRING
},
createdAt: {
allowNull: false,
type: Sequelize.DATE
},
updatedAt: {
allowNull: false,
type: Sequelize.DATE
}
});
and the model definitions:
const User = sequelize.define('User', {
id: {
allowNull: false,
autoIncrement: true,
primaryKey: true,
type: DataTypes.INTEGER
},
email: {
allowNull: false,
type: DataTypes.STRING,
unique: true
},
passhash: {
allowNull: false,
type: DataTypes.STRING
},
currency: {
type: DataTypes.STRING,
defaultValue: 'lev'
}
}, {
classMethods: {
associate: function (models) {
User.hasMany(models.Income, {
foreignKey: 'userId',
});
User.hasMany(models.Expense, {
foreignKey: 'userId',
});
}
}
});
const Expense = sequelize.define('Expense', {
id: {
allowNull: false,
autoIncrement: true,
primaryKey: true,
type: DataTypes.INTEGER
},
value: {
allowNull: false,
type: DataTypes.FLOAT
},
text: {
type: DataTypes.STRING
},
expenseCategoryId: {
allowNull: false,
type: DataTypes.INTEGER
},
userId: {
allowNull: false,
type: DataTypes.INTEGER
}
}, {
classMethods: {
associate: function (models) {
Expense.belongsTo(models.User, {
foreignKey: 'userId'
});
Expense.belongsTo(models.ExpenseCateogory, {
foreignKey: 'expenseCateogoryId',
});
}
}
});
const ExpenseCategory = sequelize.define('ExpenseCategory', {
id: {
allowNull: false,
autoIncrement: true,
primaryKey: true,
type: DataTypes.INTEGER
},
category: {
allowNull: false,
type: DataTypes.STRING
}
}, {
classMethods: {
associate: function (models) {
ExpenseCateogory.hasMany(models.Expense, {
foreignKey: 'expenseCategoryId'
});
}
}
});

Answer 1

I got an working answer. In this example i have a scheme where a department can have a lot of positions. The Position will include the department and the department will include its positions.
models/Department.js
module.exports = (sequelize, DataTypes) =>
{
const Sequelize = require('sequelize');
const Department = sequelize.define('Department',
{
...
}
Department.associate = function(models) {
Department.hasMany(models.Position, {
foreignKey: 'department_id',
as: 'positions'
});
};
return Department;
};
models/Position.js
module.exports = (sequelize, DataTypes) =>
{
const Sequelize = require('sequelize');
const Position = sequelize.define('Position',
{
...
}
Position.associate = function(models) {
Position.belongsTo(models.Department, {
foreignKey: 'department_id',
as: 'department',
onDelete: 'CASCADE'
});
};
return Position;
};
controllers/departmentController.js
exports.all = async function(req, res)
{
return Department
.findAll({include: [ 'positions' ]})
.then((data) => {
if (!data) { return res.status(400).json({status: 400,message: 'Registro não encontrado', data: data }); }
return res.status(200).json(data);
})
.catch((error) => {
return res.status(400).json({message: 'Falha no banco de dados.', data: error})
});
};
controllers/positionController.js
exports.all = async function(req, res)
{
return Position
.findAll({include: [ 'department' ]})
.then((data) => {
if (!data) { return res.status(400).json({status: 400,message: 'Registro não encontrado', data: data }); }
return res.status(200).json(data);
})
.catch((error) => {
console.log(error);
return res.status(400).json({message: 'Falha no banco de dados.', data: error})
});
};

Answer 2

Just change this sections
classMethods: {
associate: function (models) {
ExpenseCateogory.hasMany(models.Expense, {
foreignKey: 'expenseCategoryId'
});
}
}
to
ExpenseCategory.associate = (models) => {
ExpenseCategory.hasMany(models.style,{
as:'expensecategories'
});
}
so the model in full will follow this structure and the other models as well
const ExpenseCategory = sequelize.define('ExpenseCategory', {
id: {
allowNull: false,
autoIncrement: true,
primaryKey: true,
type: DataTypes.INTEGER
},
category: {
allowNull: false,
type: DataTypes.STRING
}
});
ExpenseCategory.associate = (models) => {
ExpenseCategory.hasMany(models.style,{
as:'expensecategories'
});
}
return ExpenseCategory;
This is with reference to this youtube video https://www.youtube.com/watch?v=SaVxJrTRkrI and this example from github for sequelize examples on associations for models https://github.com/sequelize/express-example/tree/master/models