Lucid: Error: this.belongsTo is not a function when second parameter is not a primaryKey

[rauschmerscen]

Note: This is a very complex application (I've chosen to build upon AdonisJS), therefore, I am going to share only pieces of code that are necessary so we get to solution fast.
I have built and deployed several apps with AdonisJS but this is the first time I've met this issue.
If a solution already exists to this exact issue, kindly advise.

What I am trying to achieve

• I would like to make a OneToMany relation between two models Product and Currency.
• The constraint here is, though I have an incremental Integer ID Primary Key on Currency, I cannot use it's primary key as a foreignKey in the Products table. I must use a 3 letter string like 'usd' or 'gbp' to relate both the models.
• So I created a 'currency' column in both tables: the 'currency' column in the Products Table points to the 'currency' column in Currencies Table.

Issue

When I call this relation via EagerLoading with, I get an error:
Error: this.belongsTo is not a function

Now, I have been through the documentation several times. It does say that the second parameter should be the primary key of the model when defining the belongsTo relation.
I find this an unnecessary constraint in my opinion, one should be able to choose what relation should form though what columns.

Request

I'd like to make a request for the possibility of:
belongsTo(relatedModel, anyKey /* focus */, foreignKey)

instead of:
belongsTo(relatedModel, primaryKey /* focus */, foreignKey)

I also use Laravel for applications that require PHP, and it is possible there.

Migrations

this.create('currencies', (table) => {
    table.increments()
    ...
    table.string('symbol')
    table.string('name')
    table.string('currency') // points to products.currency
    ...
})

```javascript
this.create('products', (table) => {
table.increments()
...
table.string('title')
table.string('description')
table.string('currency') // points to currencies.currency
...
})

#### Relations

```javascript
class Currency extends Model {
    products () {
        return this.hasMany('App/Models/Product', 'currency', 'currency') 
        // since both columns are named currency
    }
}

```javascript
class Product extends Model {
currency () {
return this.belongsTo('App/Models/Currency', 'currency', 'currency')
}
}

#### Controller action

```javascript
class ProductController
{
    async all ({ request })
    {
        return await Product.query().with('currency').fetch()
        // I've simplified the query so that it we can focus on with('currency')
    }
}

Package version

"@adonisjs/framework": "^5.0.9",
"@adonisjs/lucid": "^6.1.3",

[rauschmerscen]

hello? anybody?

[verdonarthur]

I think the problem here is that Lucid ORM don't understand if it must join on the function "currency" or on the column "currency".
To fix this situation, I think the best solution is to rename the column like that for example:

// solution 1
class Product extends Model {
    currency () {
        return this.belongsTo('App/Models/Currency', 'currency_rel', 'currency')
    }
}

// solution 2
class Product extends Model {
    currencyRel () {
        return this.belongsTo('App/Models/Currency', 'currency', 'currency')
    }
}

[RomainLanz]

Hey @rauschmerscen! 👋

Could you please create a repository with the minimum amount of code to reproduce your issue?

[rauschmerscen]

@verdonarthur Yes. your second solution renaming the relation did work.
I did not try the first since I cannot change column names in this project).
Thank you very much.

I must mention here that even when I created another renamed relation currencee() and stopped using currency(), it did not work until I had to completely remove currency(), and then it worked.
class Product extends Model { // had to completely remove it currency () { return this.belongsTo('App/Models/Currency', 'currency', 'currency') } // renaming relation currency currencee () { return this.belongsTo('App/Models/Currency', 'currency', 'currency') } }

[rauschmerscen]

@RomainLanz Issue Reproduce Repo

[RomainLanz]

I see that you are not following our convention, FK should be named xxx_id.
Please, can you try by following the convention and let me know if it works?

[rauschmerscen]

I cannot rename columns. Laravel doesn't follow this convention either.

[zelucena]

Same issue here. I have several projects sharing the same DB so I must not change column names. I don't understand why this.belongsTo allows you to override the primary key if it will impose you a convention regardless.

[rauschmerscen]

I think it's most probably a Knex.js issue, I'm not sure as I've not used it myself. But if it isn't then removing this convention allowing to choose whatever column name would provide ease and a sense of freedom in many scenarios.

[stale[bot]]

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