Using SQL GROUP BY to Summarize Patient Data

As a clinician, I’m used to looking at patient data in aggregated reports: counts, averages, and trends. SQL’s GROUP BY feels like the database version of those summaries.

For example, I could group patient visits by department to see how many visits occurred in each. In a pharmacy context, I could group by drug name to see total administrations in a month.

In practice:

SELECT Department, COUNT(*) AS TotalVisits
FROM PatientVisits
GROUP BY Department;

Practical idea:

• Group lab tests by test type to see monthly volumes.
• Group prescriptions by prescriber to identify high-use medications.

It’s a small step toward turning raw data into meaningful insights.