Table Creation With Constraint : CUSTMER_DTL

TABLE NAME : CUSTOMER_DTL

create table customer_dtl
(
cust_no varchar2(6) references customer_mst,
bill_mon varchar2(3),
prev_read number(5),
curr_read number(5),
unit_price number(5,2) check(unit_price>0),
due_date date);

insert into customer_dtl values('ANA001','NOV',1234,2545,5.50,'26-DEC-05');
insert into customer_dtl values('VVN001','DEC',256,365,5.50,'20-JAN-06');
insert into customer_dtl values('ANA002','NOV',245,578,5.50,'26-DEC-05');
insert into customer_dtl values('BAK001','DEC',45,145,5.50,'20-JAN-06');
insert into customer_dtl values('VVN002','DEC',254,545,5.50,'20-JAN-06');
insert into customer_dtl values('ANA003','NOV',2255,2365,5.50,'26-DEC-05');