Projection and Selection Practice Questions in relational algebra

 Projection and Selection Practice Questions:

Student

S_ID	NAME	Branch
1	A	CS
2	B	IT
3	C	CS
4	D	CS
5	E	EE
6	F	EC
7	G	EE

 

 

1. Find the names of all students from CS branch.

Π name (σ Branch = ‘CS’ (Student))

Account (account_no, branch_name, balance)

• Find those account numbers where balance is less than 1000.

Π account_no (σ balance<1000 (Account))

Loan(loan_no, branch_name, amount) 

• Find those loan numbers which are from Delhi branch with amount greater than 1000.

Π loan_no (σ branch_name=’Delhi’ ^ amount>1000 (Loan))

 

Branch (Branch_name, Branch_city, assets) 

• Find branch_name and branch_city with assets more than 100000.

Π branch_name , branch_city (σ assets>100000 (Branch))