I’m trying to write the sql for a database for a sample video rental store. It has to be so that a customer can rent only 10 videos maximum at a time. Each video rental stores the date of the rental, and the date it was returned. How do I add this constraint in?
let’s assume using sql, they are:
create table member(memberID integer primary key);
create table rentals(member integer foreign key references member(memberID),
video integer foreign key references video(videoID),
dateRented datetime not null, dateReturned datetime,
constraint pk primary key (member,video));
create table video(videoID integer primary key);
now I’m thinking that to represent a video still checked out, I add an entry to the rental table with the returnedDate as null. How do I make it so only a max of 10 videos can be rented out at once per member?