Sequelize association not returning value - postgresql

Question

I am trying to understand associations in sequelize and I am able to get one association to work but when I replicate the same query nothing gets returned. I don't understand the relationships that well even after reading the user guide
I can get the data from "stages" but not able to successfully join the "status" table and retrieve the data
I was able to find a workaround too where you can create the association from within findALL()
db.leads
.findAll({
attributes: ["id", "name", "title", "name", "title", "company", "workPhone", "mobilePhone", "otherPhone", "email", "dateCreated"],
include: [
{
model: db.stages,
association: db.leads.hasMany(db.stages, { foreignKey: "id", targetKey: "id" }),
on: {
[Op.and]: [
db.sequelize.where(
db.sequelize.col("stages.id"),
Op.eq, // '=',
db.sequelize.col("leads.stageID")
),
],
},
attributes: ["name"],
},
{
model: db.status,
association: db.leads.belongsToMany(db.status, { through: "id" }),
on: {
[Op.and]: [
db.sequelize.where(
db.sequelize.col("status.id"),
Op.eq, // '=',
db.sequelize.col("leads.statusID")
),
],
},
attributes: ["name"],
},
],
where: {
ownerID: req.query.ownerID,
},
subQuery: false,
duplicating: false,
})
This is what gets returned:
{
"id": "920cc536-48ae-40ee-8c5b-e1bfedbec602",
"name": "Dummy Lead",
"title": "Dummy",
"company": "Dummy",
"workPhone": "000-000-0000",
"mobilePhone": "000-000-0000",
"otherPhone": "000-000-0000",
"email": "Dummy#Dummy.com",
"dateCreated": "2022-06-18T13:30:09.676Z",
"stages": [
{
"name": "Qualify"
}
],
"status_types": []
}
Below are my tables:
Leads:
Stages:
Status:

Answer 1

In general, I believe the recommended approach to associations is to set them up in your models. This will make your queries easier to write, and also help from a DRY perspective. With the associations set up in models, your include would look something like
include: [
{
model: db.stages
attributes: ['name']
}
]
This would LEFT JOIN Stages with Leads. (NB: By adding a property of required: true to the object, you can make that perform an INNER JOIN).
The associations you're trying to call in these queries also do not really seem to match your table structure. If Leads hasMany Stages, then why is there a StageId in the Leads table? Having the foreign key in Leads would suggest that this is a hasOne or belongsTo relation from the Leads side. If Leads SHOULD have many Stages, then the foreign key should exist on the Stages table, so that multiple Stages can be associated to a single Lead.
Defining Leads with a belongsToMany relationship on Status also appears to be incorrect. BelongsToMany is the association method for Many to Many relationships through a junction table. If you do want to have a Many to Many relationship here (Where a Lead can have many Statuses, and Statuses can belong to many Leads), you will need to create that belongsToMany association on each side with a junction table (LeadStatuses). If a Lead should only have one status, however, the association should be lead.belongsTo() and status.hasMany().
I would take a long read about Sequelize Associations to try to take all of this in. It's challenging stuff that you will likely need to revisit several times, but it will make your life much easier once implemented correctly.