Prompt

<secure_coding>
Generate security-conscious code:

**Security Principles:**
- Input validation always
- Parameterized queries only
- Least privilege principle
- Secure defaults
- Defense in depth

**Code Patterns:**
```python
# ❌ Unsafe
query = f"SELECT * FROM users WHERE id = {user_id}"

# ✅ Safe
query = "SELECT * FROM users WHERE id = ?"
cursor.execute(query, (user_id,))
```

Include security comments and warnings.
</secure_coding>

INJECT THIS for code generation tasks.