Database Ass

Question One

Compute the closure (F+) of the following set F of functional dependencies for relation schema R(A, B, C, D, E).

A → BC

CD → E

B → D

E → A

List the candidate keys for R.

Ans.

Question Two

Write the following queries in Relational Algebra, for the following bank schema:

account (ano, bname, balance)

branch (bname, bcity, assest)

customer (Cname, cstreet, ccity)

loan (lno, bname, amount)

deposit (cname, ano)

borrower (cname, ino)

1. Select all loan tuples where branch name is Abha. :

1. Select all loan tuples where branch name is Abha and loan amount less than 200000.

Question Three

Using the above bank schema, find the Tuple Relational Calculus queries, for the following:

1. Find the loan with amount more than 150,000.

1. Find loan number for each loan of amount greater than 150,000

Ans:

Question Four

Given the three tables below, write the following queries.

Customer

custNo	custName	custSt	custCity	age
1	C1	Olaya St	Jeddah	20
2	C2	Mains St	Riyadh	30
3	C3	Mains Rd	Riyadh	25
4	C4	Mains Rd	Dammam
5	C5	Mains Rd	Riyadh

Product

prodNo	prodName	prodDes	price
100	P0	Food	100
101	P1	healthy Food	100
102	P2		200
103	P3	self_raising flour,80%wheat	300
104	P4	network 80x	300

Order

ordNo	ordDate	custNo	prodNo	quantity
R03010101	01-jan-2003	C01	100	2
R03010203	02-jan-2003	C01	101	1
R03010102	01-jan-2003	C2	102	1
R03010103	01-jan-2003	C343	100	2
R03010301	03-jan-2003	C01	101	1
R03030601	06-mar-2003	C2	100	10

1. A DDL command to build order table, including all integrity constraints. Make sure that or dDate value exists and quantity value is always positive.

1. A DML command to answer: How many orders were made by customer C01 and how many products pieces did he order?

1. A DML command to list customers who have ordered the product 100. (Hint: use join)

1. A DML command to find products with price more than average (Hint: use nested queries) Ans:

Question Five

Describe Server-side Scripting and Client-side Scripting in detail. Also, discuss the key difference between Server-side Scripting and Client-side Scripting.

Ans.