in sqlite

these are the tables:

create table users ( email char(20), name char(16), pwd char(4), city char(15), gender char(1), primary key (email) ); create table products ( pid char(4), descr char(20), primary key (pid) ); create table sales ( sid char(4), lister char(20) not null, pid char(4), edate date, descr char(25), cond char(10), rprice int, primary key (sid), foreign key (lister) references users, foreign key (pid) references products ); create table bids ( bid char(20), bidder char(20) not null, sid char(4) not null, bdate date, amount float, primary key (bid), foreign key (bidder) references users, foreign key (sid) references sales ); create table items ( sid char(4), no int, pid char(4), descr char(25), primary key (sid,no), foreign key (sid) references sales on delete cascade, foreign key (pid) references products ); create table reviews ( reviewer char(20), reviewee char(20), rating float, rtext char(20), rdate date, primary key (reviewer, reviewee), foreign key (reviewer) references users, foreign key (reviewee) references users ); create table previews ( rid int, pid char(4), reviewer char(20) not null, rating float, rtext char(20), rdate date, primary key (rid), foreign key (pid) references products, foreign key (reviewer) references users ); create table endorses ( rid int, endorser char(20), primary key (rid, endorser), foreign key (rid) references previews, foreign key (endorser) references users );

Question:

For each user who has had some bids, list the user email, the total number of distinct sales the user has had bids on, the number of winning bids, and the total dollar amount of the wining bids. The user has a winning bid if the sale is over (i.e., the end date is in the past), the user has the highest bid and the bid amount is not less than the reserved price. The result should include users who have no winning bids. Hint: subqueries can be used in the from clause.