Insert multiple values with the same foreign key - sqlite

Question

I have two tables that reference each other:
CREATE TABLE Room
room_id INTEGER PRIMARY KEY,
room_name TEXT UNIQUE NOT NULL;
CREATE TABLE Item
item_id INTEGER PRIMARY KEY,
room_id INTEGER,
item_name TEXT,
FOREIGN KEY (room_id) REFERENCES Room (room_id) ON UPDATE RESTRICT ON DELETE RESTRICT;
Now I want to add a new room and add a few dozen items to go into it.
INSERT INTO Room(room_name) VALUES ('Living Room');
Let's say I don't know how many rooms there are, and I just want to put stuff into the living room. To do that, I need to select the right room_id. For a single item this is not too bad:
INSERT INTO Item(room_id, item_name)
SELECT room_id, 'Couch' AS item_name FROM Room WHERE room_name = 'Living Room';
But what if I want to insert a bunch of values simultaneously. I tried using last_insert_rowid, but that does not treat the entire INSERT as a single transaction. In other words, the last ID keeps incrementing
INSERT INTO Item (room_id, item_name)
VALUES
(last_insert_rowid(), 'Chair'),
(last_insert_rowid(), 'TV'),
(last_insert_rowid(), 'Carpet');
I would like to avoid having to use the SELECT on each new row. Is there a way to insert multiple values into Item, while referencing the last known room_id in Room?
Something in the nature of a CROSS JOIN would likely be very useful, but I don't know how to get the constants to behave in that case
The end result I am looking for is for Room to look like this:
room_id | room_name
--------+-----------
1 | Living Room
And Item like this:
item_id | room_id | item_name
--------+---------+-----------
1 | 1 | Chair
2 | 1 | TV
3 | 1 | Carpet

Answer 1

You can use a CROSS join of the id that you get from the new room to a CTE that returns the items that you want to insert:
WITH cte(item_name) AS (VALUES ('Chair'), ('TV'), ('Carpet'))
INSERT INTO Item (room_id, item_name)
SELECT r.room_id, c.item_name
FROM Room r CROSS JOIN cte c
WHERE r.room_name = 'Living Room';
See the demo.
If you are using a version of SQLite that does not support CTEs use UNION ALL in a subquery:
INSERT INTO Item (room_id, item_name)
SELECT r.room_id, c.item_name
FROM Room r
CROSS JOIN (
SELECT 'Chair' item_name UNION ALL
SELECT 'TV' UNION ALL
SELECT 'Carpet'
) c
WHERE r.room_name = 'Living Room';
See the demo.