Sequelize fetch include data based on alias where condition - node.js

Question

I have two tables Employee and Department
Department
const Department = Sequelize.define(
"Department",
{
id: {
type: DataTypes.INTEGER,
autoIncrement: true,
primaryKey: true,
},
name: {
type: DataTypes.STRING,
allowNull: false,
},
},
{
underscored: true,
timestamps: true,
paranoid: true,
modelName: "Department",
tableName: "departments",
},
);
Department.associate = function (models) {
// associations can be defined here
models.Department.hasMany(models.Employee, {
foreignKey: "department_id",
as: "employees",
});
};
return Department;
};
Employee
const Employee = Sequelize.define(
"Employee",
{
id: {
type: DataTypes.INTEGER,
autoIncrement: true,
primaryKey: true,
},
name: {
type: DataTypes.STRING,
unique: true,
allowNull: false,
},
status: {
type: DataTypes.STRING,
defaultValue: "active",
},
departmentId: {
type: DataTypes.INTEGER,
},
},
{
underscored: true,
timestamps: true,
modelName: "Employee",
tableName: "employees",
},
);
Employee.associate = function (models) {
models.Employee.belongsTo(models.Department, {
foreignKey: "department_id",
as: "department",
});
};
return Employee;
};
Now I have to fetch the list of employees and putting a filter of department_id = 1
const { departmentId } = req.body;
const employees = await Employee.findAll({
include: [
{
model: Department,
where: {
id: departmentId,
},
},
],
});
I am getting the issue. Department is mapped by association "departments"
Cannot fetch the data.

Answer 1

I found the answer on sequelize docs
const employees = await Employee.findAll({
include: [
{
association: "department", // this is the place to change
where: {
id: departmentId,
},
},
],
});
Learnings:
We will not be able to put association and model together.
We will be able to use the Model if no association is there.
We will be able to use association if there is one.
References: https://sequelize.org/master/manual/eager-loading.html#:~:text=You%20can%20also%20include%20by%20alias%20name%20by%20specifying%20a%20string%20that%20matches%20the%20association%20alias