Trigger , Database Management System

Assignment Help:

Flights(FlightNo, DeptDateTime, Origin, ArrivalDateTime, Destination, Capacity, SoldSeats) Tickets(FlightNo, Seat, CustID)

Where
- flightNo is the PK of the flights table
- DeptDateTime holds the date and time of the flights departure
- Origin holds the airport code (e.g. RKE) of the flights origin
- ArrivalDateTime holds the date and time of the flights arrival
- Destination holds the airport code (e.g. ATL) of the flights destination
- Capacity is the number of passenger seats the flight can hold
- SoldSeats is the number of seats that are currently sold

- FlightNo+Seat is the PK of the Tickets Table
- FlightNo in the Tickets Table is an FK referencing the Flights Table
- Seat is the seat assigned to that ticket (e.g. 7B)
- CustID is the ID number of the customer that is assigned to that seat

Write a trigger or triggers that:
- increments the SoldSeats field when a ticket is inserted
- raises an exeception when an attempt to insert a ticket occurs
  if the flight is already sold out
- decrements the SoldSeats field when a ticket is deleted

To provide appropriate transaction control your trigger should lock the associated flight row in the flights table before attempting to update the SoldSeats field.

Add sample data and test your triggers.

Have your triggers finished with some sample data entered by the start of class on November 16th.


Related Discussions:- Trigger

Replicating data, Replicating Data One approach that may support effici...

Replicating Data One approach that may support efficient access to dissimilar applications as above may be to give access to every of the applications from dissimilar replicate

Fire department, The State of Newyork certifies firefighters throughout sta...

The State of Newyork certifies firefighters throughout state keep track all of them, as well as the state’s of fire departments. Each fire department has unique department number

Give detail explanation about cross-section of twisted pair, The cross-sect...

The cross-section of twisted pair The cross-section of each and every strand of the twisted pair is π/4 square mm. A 10-km length of this type of material, with two strands per

Implementation of integrity rules, Question 1 Describe the following- ...

Question 1 Describe the following- Clustering Indexing Question 2 Explain the following with suitable real time examples- Implementation of Integrity rules

Database administrator, Database Administrator One of the main perpos...

Database Administrator One of the main perpose for having the database management system is to have control of both data or programs accessing that data. The person having li

Create student database and retrieve course taught by king, Create student ...

Create student database and retrieve course name taught by king? STUDENT (name, student#, class, major) COURSE (course name, course#, credit hours, department) SECTION (secti

Binary relationships, One-to-one relationship: For every 1:1 relationshi...

One-to-one relationship: For every 1:1 relationship type R in the ER diagram including two entities E1 and E2 we take one of entities (say E1) preferably with total participatio

Why containment is important in oosystems, Why containment is important in ...

Why containment is important in oosystems? Containment is an significant concept in oosystems because it allows dissimilar users to view data at different granularities.

What are object interaction diagrams, What are object interaction diagrams?...

What are object interaction diagrams? Object interaction diagrams are the diagrams that used to describe order in which messages are communicated in execution of an operation,

Calculate the record size r in bytes, An employee record has the following ...

An employee record has the following structure struct employee { int eno; char name[22]; float salary; char dept[10];}; (i) Calculate the record size R in bytes.

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd