Below is the changes you need to done
ON DELETE CASCADE trigger is used to perform such
action.
Create table Appt(
              Â
pid numeric Foreign Key references patient(pid),
              Â
ptname varchar(50) Foreign Key references patient(name) ON
DELETE CASCADE,
              Â
dob date Foreign Key references patient(dob),
              Â
dr varchar(20),
              Â
appdate date,
              Â
apptime time,
);
and
Create table Patient(
              Â
pid numeric primary key,
              Â
name varchar(50),
              Â
dob date,
              Â
pdr varchar(20),
              Â
phnum numeric(10),
            Â
email varchar(50),
              Â
addr varchar(50)
}
