'datetime']; } public function prescription(): BelongsTo { return $this->belongsTo(Prescription::class, 'prescription_id'); } public function prescriptionItem(): BelongsTo { return $this->belongsTo(PrescriptionItem::class, 'prescription_item_id'); } public function drugBatch(): BelongsTo { return $this->belongsTo(DrugBatch::class, 'drug_batch_id'); } }