How to build a query with multi level relationship

[pk4all]

Hello !

I have a user model with relationship with education model

@hasOne(() => Education,{
    localKey: 'id',
    foreignKey: 'uid'
  })
  public education: HasOne<typeof Education>

await User.query().preload('education').where education is ABC

How to write query with where for find a specific education category.

[thetutlage]

Covered in the docs https://preview.adonisjs.com/guides/model-relations/introduction#relationship-constraints

[pk4all]

@thetutlage Thanks.
But I am getting an error => Property 'whereHas' does not exist on type 'ModelQueryBuilderContract<typeof User, User>'"

[thetutlage]

Make sure you are running latest version of lucid. Docs are always your best friend. https://preview.adonisjs.com/releases/lucid/version-8_3_2/

[pk4all]

@thetutlage Thanks.
I have installed 8.4.2. But I am getting a new error on on my model subquery

@hasMany(() => UserMasterGodown,{
    localKey: 'id',
    foreignKey: 'masterFor',
    onQuery: (query) => query.preload('master').where('masterType', 6)
  })
  public hashtags: HasMany<typeof UserMasterGodown>

error is =>

(property) ModelQueryBuilderContract<Model extends LucidModel, Result extends unknown = InstanceType<Model>>.preload: Preload<UserMasterGodown, RelationQueryBuilderContract<typeof UserMasterGodown, any>> | Preload<UserMasterGodown, RelationSubQueryBuilderContract<...>>
Define relationships to be preloaded

This expression is not callable.
  Each member of the union type 'Preload<UserMasterGodown, RelationQueryBuilderContract<typeof UserMasterGodown, any>> | Preload<UserMasterGodown, RelationSubQueryBuilderContract<...>>' has signatures, but none of those signatures are compatible with each other

[thetutlage]

Oh yes, you need to wrap your preload code inside an if statement.

onQuery: (query) => {
  if (!query.isRelatedSubQuery) {
    query.preload('master').where('masterType', 6)
  }
}

The conditional is required so that you are not preloading when your onQuery hook is executed for constructing a whereHas subquery. I will cover this properly in the docs

[pk4all]

@thetutlage Thanks a lot for such type quick support.
It's perfectly working for me.