According to Sakila database:

a) Write an Sql sentence that gives Total Amount of payment for each staff

b) Write an sql sentence that gives only number of payment_id from payment table that matches with rental table. Write your sql sentences using left and right join operands. Is there any difference between left and right join queries? If so, define the reason.

c) Write an sql sentence that gives customer names and their -individual- total payment amount.

d) Write an sql sentence that gives countries and total customers from that countries.