Repeat Visitors

Return plates that visited more than once, with the number of visits.

Table schema

Parking(id INT PRIMARY KEY, plate VARCHAR(8), time_in DATETIME, time_out DATETIME)

Sample data

id | plate | time_in | time_out
1 | A1 | 2026-06-01 08:00:00 | 2026-06-01 10:30:00
2 | B2 | 2026-06-01 09:00:00 | 2026-06-01 09:45:00
3 | A1 | 2026-06-01 13:00:00 | 2026-06-01 14:00:00
4 | C3 | 2026-06-01 15:00:00 | NULL
5 | D4 | 2026-06-01 16:00:00 | NULL