Depends on how thick a braid and mono you are using. In the larger, heavier weights and thicknesses then knots can work - though not optimally.
In the smaller, thinner weights and thicknesses then IMHO (having experimented at length some six or seven years ago) you have to use a micro swivel.
Thin braid knots to a metal swivel loop ok. Just don't use a blood knot, as stated. Grinner or variant.
Anything else but a swivel, whether braid or mono or whatever, it simply cuts through like a cheesewire through.... well, cheese