Best practices for complex queries

export function listOlympiadsQuery(db: GDDB) {
  return db
    .select({
      id: OlympiadTable.id,
      slug: OlympiadTable.slug,
      year: OlympiadTable.year,
      startDate: OlympiadTable.startDate,
      endDate: OlympiadTable.endDate,
      olympiadType: OlympiadTable.olympiadType,
      realOlympiad: OlympiadTable.realOlympiad,
      city: {
        id: CityTable.id,
        name: CityTable.name,
        slug: CityTable.slug,
        country: {
          id: CountryTable.id,
          name: CountryTable.name,
          slug: CountryTable.slug,
          flag: {
            id: FlagTable.id,
            png: FlagTable.png
          }
        }
      }
    })
    .from(OlympiadTable)
    .innerJoin(CityTable, eq(OlympiadTable.cityId, CityTable.id))
    .innerJoin(
      OlympiadCountryTable,
      and(
        eq(OlympiadCountryTable.olympiadId, OlympiadTable.id),
        eq(OlympiadCountryTable.countryId, CityTable.countryId)
      )
    )
    .innerJoin(CountryTable, eq(OlympiadCountryTable.countryId, CountryTable.id))
    .leftJoin(FlagTable, eq(OlympiadCountryTable.flagId, FlagTable.id))
    .where(eq(OlympiadTable.realOlympiad, true))
    .orderBy(desc(OlympiadTable.startDate))
    .prepare('listOlympiadsQuery');
}

const query = listOlympiadsQuery(db);
const result = await query.execute();