Longest Gap Between Library Visits

Problem

Table: `library_visit`

| Column Name | Type |
|---|---|
| patron_id | int |
| visit_day | date |

There is no primary key, but for any patron all `visit_day` values are distinct. Each row records that `patron_id` visited the library on `visit_day`.

For each patron, report the **longest gap in days** between two of their visits. For the gap that follows a patron's most recent visit, treat the period as ending on the reference date **2026-01-01**. Output `patron_id` and the gap as an integer aliased `longest_gap`, ordered by `patron_id`.

Tables

Example rows — the live problem includes the full dataset.

Expected output

Your answer should return 2 rows with the columns patron_id, longest_gap.

Starter code (SQL)

SELECT *
FROM library_visit;

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