The veterinarians want to know the total for the invoices that have been paid.

a$.$ SELECT SUM$($INVOICE$)$

FROM APPOINTMENTS;

b$.$ SELECT SUM$($INVOICE$)$

FROM APPOINTMENTS

WHERE PAID $=Y$ :

c$.$ SELECT SUM$($INVOICE$)$

FROM APPOINTMENTS

WHERE PAID $=1$;

The veterinarians want the information for appointments scheduled between October $19$ th and October $30.$

a$.$ SELECT PET$\_$NAME, OWNER$\_$LNAME, APPOINTMENT$\_$REASON, APPOINTMENT$\_$DATE FROM Owner, Pet, Appointments

WHERE OWner.OWNER$\_$ID $=$ Pet.OWNER ID

AND Pet.PET$\_$ID $=$ Appointments.PET$\_$ID

AND APPOINTMENT$\_$DATE BETWEEN $\text{'}2019-10-19$ AND$-2019-10-30\text{'}$