Check if DRG codes are the same for every line item within the same claim $($check all claims$)$

Check if primcipan diagnosis and diagnosis code $1$ are always the same.$$

For all claims with DRG code $963,$ calculate average, minimum and maximum costs associated with each principal diagnosis

Identify all patients that have at least one claim with DRG code $963.$ What other DRG codes these patients have? What are principan diagnoses on their claims?