Explain core DBMS concepts and how you would model and query data for a real application.
Use the supplied relational model to demonstrate primary keys, foreign keys, normalization, NULL handling, and a query that summarizes approved claims for every policyholder.
policyholder_name, policy_status, approved_claim_count, approved_claim_total, claim_summary| Column | Type | Description |
|---|---|---|
| policyholder_idPK | INT | Unique policyholder identifier |
| policyholder_name | VARCHAR(120) | Policyholder full name |
| policy_status | VARCHAR(20) | Current policy status |
| Column | Type | Description |
|---|---|---|
| claim_idPK | INT | Unique claim identifier |
| policyholder_id | INT | Referenced policyholder |
| claim_date | DATE | Date the claim was submitted |
| claim_type | VARCHAR(40) | Type of insurance claim |
| claim_status | VARCHAR(20) | Current claim status |
| claim_amount | DECIMAL(12,2) | Claim amount in dollars |