There is a sales table
create table sales
(
customer varchar(25),
product varchar(25),
day integer,
month integer,
year integer,
state char(2),
quantity integer
);

for each customer prod combination
we need the min quantity and the date for it
max quan and the date for it and the avg like this

CUSTOMER PRODUCT MAX_Q DATE MIN_Q DATE AVG_Q


Can anyone help me to write a query for this?