How to exclude association belongs-to-many from an instance in sequelize? - database

Question

I'm trying to exclude a junction model from a query with the association of a model, this is how they are associated:
Warehouse.associate = function(models) {
Warehouse.Products = Warehouse.belongsToMany(models.Product, {
as: {
singular: 'product',
plural: 'products',
},
through: models.WarehouseProducts,
foreignKey: "warehouse_id",
otherKey: "product_id",
onDelete: 'CASCADE',
onUpdate: 'CASCADE'
});
}
Product.associate = function(models) {
Product.Warehouses = Product.belongsToMany(models.Warehouse, {
as: {
singular: "warehouse",
plural: "warehouses"
},
through: models.WarehouseProducts,
foreignKey: "product_id",
otherKey: "warehouse_id",
onDelete: 'CASCADE',
onUpdate: 'CASCADE'
});
}
And this is the code that I use to retrieve the product of a warehouse:
export const prefetchWarehouse = [
validator.params.warehouse,
async function(req, res, next) {
try {
if (validator.errors(req)) {
throw validator.stack;
} else {
req.warehouse = await Warehouse.findById(req.params.warehouse);
next();
}
} catch (err) {
next(err);
}
}
];
export const getProduct = [
validator.params.product,
async function(req, res, next) {
const result = await req.warehouse.getProducts({
where: {
id: {
[Op.eq]: req.params.product
}
},
plain: true
});
console.log('===>', result);
}
]
And this is the output:
Is there anyway to avoid not getting back that association?

Answer 1

I've ran across this behavior, and i solved it by just setting joinTableAttributes to an empty array like so joinTableAttributes: [].
export const getProduct = [
validator.params.product,
async function(req, res, next) {
const result = await req.warehouse.getProducts({
joinTableAttributes: [], // Here
where: {
id: {
[Op.eq]: req.params.product
}
},
plain: true
});
console.log('===>', result);
}
]
hope that helps you.

Answer 2

One way to solve this is using the junction model in my handler to avoid it:
export function WarehouseProducts(WarehouseProducts) {
WarehouseProducts.associate = function(models) {
WarehouseProducts.Products = WarehouseProducts.belongsTo(models.Product, {
as: "product"
});
};
}
And then in the handler:
const result = await WarehouseProducts.findOne({
where: {
warehouse_id: { [Op.eq]: req.params.warehouse },
product_id: { [Op.eq]: req.params.product }
},
include: [ "product" ]
});
res.json(result.product);
Although, it would be nice to doing in the way that I was looking for because the same function "prefetchWarehouse" is reused in others endpoints, so that would help to avoid. Even though the code looks more optimized, but anyway, if someone else has any suggestion I would appreciate it.
Thanks.