[V5] How to add an alias on a Lucid query

[douglasdnzcarvalho]

Basically, I have three tables: tableA, tableB and tableC (which is a pivot table). Im trying to make a query on tableA searching for records that are not present in the tableC based on a key from tableB. The function bellow works and returns a json array (as expected) in the data property:

static async getNotInPivot(tableB_id: number, tableA_ids: number[] | undefined, page: number, perPage: number): Promise<{ meta: SimplePaginatorMeta, data: TableA[] }>{
    const result = await Database.query()
    .from(`${TableA.table} as a`)
    .where((builder) => {
      if(tableA_ids != undefined) builder.whereIn('a.id', tableA_ids);

      return builder;
    })
    .whereNotExists((builder) => {

      return builder
          .from(`${TableC.table} as c`)
          .select('c.tablea_id')
          .whereRaw('c.tablea_id = a.id')
          .where('c.tableb_id', tableB_id);
    })
    .orderBy('a.id', 'asc')
    .paginate(page, perPage);
    
    return result.toJSON();
}

The problem is that I actually need to return a Lucid Model array cause I will use it to make some calculations and updates later, and the fields mapping is important to the final result.

I've tried change the lines Database.query().from(`${TableA.table} as a`) to TableA.query().as('a') but it gives me this error:

select count(*) as "total" from "tablea" where not exists (select "c"."tablea_id" from "tablec" as "c" where c.tablea_id = a.id and "c"."tableb_id" = $1) - missing FROM-clause entry for table "a"

Apparently the as() function is not being executed. Would anyone have any suggestions to solve the problem?