Either way is fine, it just depends whether you want authentication to be stateless.
Advantages of JWTs:
- Little or no database overhead.
- Individual back-end components can validate the token in isolation, simply by knowing the secret key.
- As authentication state is stored client-side, you cannot invalidate logins server-side.
Depending on the risk appetite of your application, this could be a big enough disadvantage for you to move all authentication logic to server-side.
Note that you could combine the two, and have the authenticated token supplied client-side validated server-side (i.e. the token inside the JWT is validated by a MAC, and the token itself is stored in a database). This protects against the situation where your session table is exposed by an attack as an attacker cannot use the session identifiers directly to hijack a session without knowing the secret key used to validate the MAC.