'"Operator does not exist: object_model #>> unknown" when using ref in leftJoinRelated with 5 tables.'

[ombak]

Hi, I'm an objection user for 5 years. I just encountered this problem when doing a join on 5 tables. I want to fill one field "product" with one of the joined tables (product, buyback, appraisal). One of those tables will have a value and fill the "product" field. I managed to do it with raw query, but when I want to use objection I have this problem operator does not exist: outlet_transaksi_detail #>> unknown. Here is the code that I have created with objection and raw query.
The problem is when I use CASE WHEN.

use raw query

export function getAllReportOutletTransakasiRaw(data) {
  return new Promise(async (resolve, reject) => {
    try {
      const { _outletUuid, _kasirUuid } = data;
      const _knex = OutletTransaksiModel.knex();
      const _results = await _knex.raw(
        `
        SELECT
          ROW_NUMBER() OVER() AS nomor,
          TO_CHAR(transaksi.created_at, 'HH12:MI:SS') AS waktu_dibuat,
          transaksi.type,
          transaksi.nomor_transaksi,
          transaksi.id AS transaksi_id,
          CASE
            WHEN product.nama IS NOT NULL
              THEN product.nama
            WHEN buyback.nama IS NOT NULL
              THEN buyback.nama
            WHEN appraisal.jenis IS NOT NULL
              THEN appraisal.jenis
            ELSE '-'
          END AS product,
          transaksi.diskon,
          details.quantity,
          details.harga,
          (details.quantity * details.harga) - transaksi.diskon AS total
        FROM public.outlet_transaksi transaksi
        LEFT JOIN outlet_transaksi_detail details
          ON details.transaksi_id = transaksi.id
        LEFT JOIN outlet_products product
          ON product.id = details.product_id
        LEFT JOIN outlet_buyback buyback
          ON buyback.id = details.buyback_id
        LEFT JOIN outlet_appraisal appraisal
          ON appraisal.id = details.appraisal_id
        WHERE transaksi.outlet_uuid = ?
          AND transaksi.status = 'done'
          AND transaksi.created_by = ?;
      `,
        [_outletUuid, _kasirUuid],
      );

      resolve(_results);
    } catch (error) {
      reject(error);
    }
  });
}

use objection

export function getAllReportOutletTransaksi(data) {
  return new Promise(async (resolve, reject) => {
    try {
      const { _outletUuid, _kasirUuid, _start, _end } = data;
      const _keyProduct = ref("details:product.nama").castText();
      const _keyBuyback = ref("details:buyback.nama").castText();
      const _keyAppraisal = ref("details:appraisal.jenis").castText();

      const _results = await OutletTransaksiModel.query()
        .select(
          "outlet_transaksi.type",
          "outlet_transaksi.nomor_transaksi",
          // "details:product.nama AS product",
          // "details:buyback.nama AS buyback",
          // "details:appraisal.jenis AS appraisal",
          "outlet_transaksi.diskon",
          "details.quantity",
          "details.harga",
          "outlet_transaksi.created_by as kasir_uuid",
        )
        .select(
          raw(
            "TO_CHAR(outlet_transaksi.created_at, 'HH12:MI:SS') AS waktu_dibuat",
          ),
          raw(
            "(details.quantity * details.harga) - outlet_transaksi.diskon AS total",
          ),
          raw("ROW_NUMBER() OVER() AS nomor"),
          raw(
            `
            CASE
              WHEN ?? IS NOT null
                THEN ??
              WHEN ?? IS NOT null
                THEN ??
              WHEN ?? IS NOT null
                THEN ??
              ELSE '-'
            END AS product
          `,
            [
              _keyProduct,
              _keyProduct,
              _keyBuyback,
              _keyBuyback,
              _keyAppraisal,
              _keyAppraisal,
            ],
          ),
        )
        .leftJoinRelated("[details]")
        .leftJoinRelated("[details.[product, buyback, appraisal]]")
        .where("outlet_transaksi.outlet_uuid", _outletUuid)
        .andWhere("outlet_transaksi.status", "done")
        .andWhere(function () {
          if (_kasirUuid) {
            this.where("outlet_transaksi.created_by", _kasirUuid);
          }
        })
        .modify("mod_range", _start, _end);

      resolve(_results);
    } catch (error) {
      reject(error);
    }
  });
}

Thanks advance for the response...