Nightly inventory model & date-range query

Hotel inventory is stored as one row per room type per night, so a stay is available only when every night from check-in up to (not including) check-out has enough free rooms.

A stay with one sold-out night in the middle

Ava and Ben work at a small inn. The computer keeps one number for each kind of room on each night: how many are still free. A guest wants to stay two nights, but one of those nights the Double room is already full.

In this lesson you'll

1Follow one run and learn how to read the picture
2Predict what changes before revealing the result
3Find a stay of 3 nights or more that really has a Double room