many-to-many script

DROP table RentalItem;
drop table item;
drop table rental;
drop table cust;

drop sequence REntityID;
create sequence REntityID start with 1000 increment by 1;

create table cust(
   custID int default next value for REntityID primary key,
   fname varchar(50),
   lname varchar(50)
);

create table rental(
   rentalID int default next value for REntityID primary key,
   startdate datetime default getdate(),
   custid int not null references cust
);

Create table item(
   itemID int default next value for REntityID primary key,
   name varchar(60),
   type varchar(30),
   rentalPrice decimal(5,2), /* this is a comment */
);

create table RentalItem(
  rentalID int references rental,
  itemID int references item,
  ActualPrice decimal(5,2) ,
  constraint RentalItem_PK primary key (rentalID, itemid),
);

INSERT INTO cust(fname, lname)
values('David','Patten'),
      ('Orson','Pratt'),
      ('Orson','Hyde');


INSERT INTO item(name, type, rentalPrice)
values('Unicycle1','cycle', 5),
      ('Unicycle2','cycle', 5),
      ('Bicycle1','cycle', 7),
      ('Mountain Bike','cycle', 8),
      ('Snowboard','Arctic', 5),
      ('Helmet1','safety', 1),
      ('Helmet2','safety', 1),
      ('Helmet3','safety', 1),
      ('Helmet4','safety', 1)
;

insert into rental(custid)
  values((select custid from cust where lname='Patten'));

insert into rentalitem values(
  (select max(rentalid) from rental),
  (select itemid from item where name = 'Mountain Bike'),
  (select rentalPrice *.95 from item where name = 'Mountain Bike')
);
insert into rentalitem values(
  (select max(rentalid) from rental),
  (select itemid from item where name = 'Helmet1'),
  0
);


insert into rental(custid)
  values((select custid from cust where lname='Patten'));

insert into rentalitem values(
  (select max(rentalid) from rental),
  (select itemid from item where name = 'Mountain Bike'),
  (select rentalPrice *.95 from item where name = 'Mountain Bike')
);