Insert all combinations of two tables in intermediate table in SQL Server

Question

My situation

I'm making a site where people can reserve meeting rooms. On the reservation form for a meeting room, I've some optional field sets like below:

ID	Name
1	Catering
2	Coffee break
3	Drinks

Here are some example meeting rooms:

ID	Name	Location
1	Dog	Brussel
2	Cat	Antwerpen
3	Chicken	Brugge
4	Cow	Gent

I'm using Microsoft SQL server 2016.

Database structure

• The fieldsets from the first code block stands inside my database in the table reservationFieldsets.
• The meeting rooms stands in the meetingRooms table.
• There is an intermediate table named meetingRoomsReservationFieldsets.

Question

Now I'll fill meetingRoomsReservationFieldsets with all rooms and all the fieldsets like below:

RoomID	FieldsetID
1	1
2	1
3	1
4	1
1	2
2	2
3	2
4	2
1	3
2	3
3	3
4	3

I've tried

I've tried to do it manually but there are a lot of rooms and too much to do that manual.

Answer 1

I've found it by the comments on the question. I use this code:

INSERT INTO meetingRoomsReservationFieldsets
SELECT meetingRooms.id, reservationFieldsets.id
FROM reservationFieldsets
CROSS JOIN meetingRooms