Использовать insert . . . select
:
insert Into Bill_Table (Patient_ID, [Med/Room], Bill,[Paid/UnPaid])
Select 13, concat('Room ID', rm.Room_ID), rt.price, 'UnPaid'
from Room_Master rm left join
Room_Type rt
on rt.Room_Type = 'Semi-Private'
where rm.[Room_No.] = 2;
В SQLite вы бы использовали оператор concat:
Insert Into Bill_Table (Patient_ID, [Med/Room], Bill,[Paid/UnPaid])
Select 13, 'Room ID' || rm.Room_ID, rt.price, 'UnPaid'
from Room_Master rm left join
Room_Type rt
on rt.Room_Type = 'Semi-Private'
where rm.[Room_No.] = 2;