Database Management System Essay Example | Topics and Well Written Essays - 1500 words - 2

Database Management System - Essay Example ata type is used in many cases which is advantageous in terms of memory management and also to make changes in the size of a field in future as required. create table Customer(Customer_no number(12) constraint CONST_PK_CUST primary key not null, Customer_town varchar2(30) not null, Customer_name varchar2(45) not null, Customer_address varchar2(80) not null ); create table Flight(Flight_code varchar2(6) constraint CONST_PK_FLIGHT primary key, Departure_day_time date not null, Departure_airport varchar2(30) not null, Arrival_time date not null, Arrival_airport varchar2(30) not null); create table Booking(Booking_ref_no number(10) constraint CONST_PK_BOOKING primary key, Booking_date date, Customer_no number(10) constraint CONST_FK_BOOKING references Customer(Customer_no), Deposit_paid varchar2(1) not null constraint CHECK_YN check(Deposit_paid in(Y,N)), Sales_rep_id number(1) constraint CONST_FK2_BOOKING references Sales_rep(Sales_rep_id) ); create table FLIGHT_SEAT(Flight_code varchar2(6) constraint CONST_FK1_FLIHTSEAT references Flight(Flight_code), Seat_no number(4) constraint CONST_FK1_FLIGHTSEAT references Seat(Seat_no), price number(5) not null,constraint CONST_PK1_FLIGHTSEAT primary key(Flight_code,Seat_no)); create table Booking_line(Booking_ref_no number(10) constraints CONST_FK1_BOOKINGLINE references Booking_line(Booking_ref_no), Flight_code varchar2(6), Flight_date date,Passenger_surname varhcar2(20), constraints CONST_PK_BOOKINGLINE primary key (Flight_code, Seat_no, Flight_date),constraints CONST_FK2_BOOKINGLINE foreign key The entity SEAT seems to be a over head in data entry and also it has some effect in database operation. The SEATNO and CLASS_CODE field in the SEAT entity can be moved into the FLIGHT_SEAT entity. In the FLIGHTSEAT entity we can have the CLASS_CODE which will solve the above issues. When the entity FLIGHT_SEAT is inserted a new row or updated any existing row the CLASS field should be first class if the seat no is less than

Case Study -( The Social Environment and Human Behavior) Essay - 1

Case Study -( The Social Environment and Human Behavior) - Essay Example This has implications on the higher economic classes from the lower. a. The greater availability of screening against abnormalities in the infants born to the elite (than in the lower economic classes) will cause a higher proportion of brighter, stronger children to the upper income class, giving them better chances for succeeding than the lower classes b. Better birth quality among the rich will tend to concentrate wealth in a small sector of society, since children born to the rich will be better qualified for the higher paying positions. Wealth distribution is thus compromised. The direct problem of the case is how to address the problem of the deterioration of Baby Kim’s health and development. The immediate question that must be resolved is whether or not Kim’s continued separation from parent should be terminated, and Kim returned home to her parents. The separation of a child from its parents is always an important issue, because it is normally presumed that parents are the best source of sustenance, support, and love for the child. The state should have an extraordinary reason, based on strong and compelling evidence, that the parents could not provide the proper care for their own child before it takes such a child away and relegates her to foster care. In this case, there appears to be no strong or compelling reason for Kim to be taken from her parents. The matter of methamphetamine use prior to Kim’s birth is not an overriding issue, since Kim’s mom would have been allowed to keep her had she agreed to sending her younger son to day care. Her refusal to send him to day care was the cause for her separation from her children and for Kim’s relegation to foster care. There is no evidence that Kim’s parent neglect their children’s care in any way whatsoever. The home is well maintained, the sons are healthy, happy and bright. In no way does any evidence show that Kim’s parents, specially her mom, is an unfit