Why should you care?

Interviewers and stakeholders ask how you would model healthcare system on Oracle — this lesson gives you a concrete starting schema.

See it live — copy this example

Run these statements in SQL Developer or SQL*Plus against your lab PDB. Prefer a practice user — not SYS — for application SQL.

-- OracleCore project sketch: Healthcare System
CREATE TABLE HEALTHCARE_SYSTEM_master (
  id           NUMBER GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
  ref_code     VARCHAR2(40) NOT NULL,
  status       VARCHAR2(20) DEFAULT 'ACTIVE',
  amount       NUMBER(14,2),
  created_at   TIMESTAMP DEFAULT SYSTIMESTAMP
);

CREATE INDEX ix_HEALTHCARE_SYST_ref ON HEALTHCARE_SYSTEM_master(ref_code);

INSERT INTO HEALTHCARE_SYSTEM_master (ref_code, amount) VALUES ('REF-1001', 1500.00);
COMMIT;

SELECT ref_code, status, amount, created_at
FROM HEALTHCARE_SYSTEM_master
WHERE status = 'ACTIVE'
ORDER BY created_at DESC;

What happened?

• IDENTITY creates ids automatically.
• ref_code is a business key.
• The index speeds lookups.
• SELECT proves the table works.

Practice next

1. Create the table in your PDB lab user.
2. Insert 3 sample rows with different statuses.
3. Run the SELECT and explain the columns to a friend.
4. Change one literal in the example and re-run.
5. Write a second example from memory without looking.

Remember

You can explain Healthcare System in plain English. You ran at least one related command or query. You know one real system where it matters.

Healthcare System

An enterprise team starts Healthcare System on Oracle with a master table and clear status values.

Outcome: You have a runnable schema sketch and a query to demo.