SQL Query Explainer

Explain the following SQL query in plain English. Break it down step by step so a junior developer can understand it.

**Query:**
```sql
{{query}}
```

**Database context:** {{db_context}}

Structure your explanation as:
1. **What this query does** — one-sentence summary
2. **Step-by-step breakdown** — explain each clause (FROM, JOIN, WHERE, GROUP BY, etc.) in order
3. **What the result looks like** — describe the shape and content of the output
4. **Potential gotchas** — any edge cases, NULLs, or performance concerns to be aware of