Who's Been Here the Longest?

Kestrel Labs is holding a small ceremony for the people who were there at the start of each team — the first hire on Engineering, the first on Sales, and so on. The office manager needs their names and the dates, one line per team.

Reading the earliest date in the whole company is easy and answers the wrong question: it would name one person and leave three teams unrepresented. Each team has its own earliest date, none of those dates is recorded anywhere, and the person attached to a date only comes back if the query hands you the whole row rather than the date on its own.

employees — one row per person. hire_date is the day they started, written as YYYY-MM-DD so that ordinary text comparison puts dates in true chronological sequence. department_id says which team they sit on.

The table already exists in the database — there is nothing to create or load.

Task: Write a query returning three columns, department_id, name and hire_date, with one row for the earliest-hired person on each team. If two people on the same team started on the same day, both appear. Rows come back in ascending department_id order.

Example output — shape only, on an invented company; the two rows for team 6 show what happens when the two longest-serving people started on the same day.