Consider the following relational schema.
Students(rollno: integer, sname: string)
Courses(courseno: integer, cname: string)
Registration(rollno: integer, courseno: integer, percent: real)
Which of the following queries are equivalent to this query in English?"Find the distinct names of all students who score more than 90% in the course numbered 107"
(I) SELECT DISTINCT S.sname
FROM Students as S, Registration as R
WHERE R.rollno=S.rollno AND
R.courseno=107 AND R.percent >90
(II) ∏sname(σcourseno = 107 ∧ percent > 90 (Registration ⋈ Students))
(III) { T | ∃S ∈ Students, ∃R ∈ Registration ( S.rollno=R.rollno ∧ R.courseno=107 ∧ R.percent > 90 ∧ T.sname=S.sname)}
(iv) { < SN >| ∃SR∃RP ( < SR, SN > ∈ Students ∧ ∈ Registration ∧ RP > 90)}
Database table by name Loan_Records is given below.
Borrower | Bank_Manager | Loan_Amount |
---|---|---|
Ramesh | Sunderajan | 10000.00 |
Suresh | Ramgopal | 5000.00 |
Mahesh | Sunderajan | 7000.00 |
What is the output of the following SQL query?
SELECT count(*)
FROM (
(SELECT Borrower. Bank_Manager FROM Loan_Records) AS S
NATURAL JOIN
(SELECT Bank_Manager, Loan_Amount FROM Loan_Records) AS T );
Consider a database table T containing two columns X and Y each of type integer. After the creation of the table, one record (X = 1, Y = 1) is inserted in the table.
Let MX and MY denote the respective maximum values of X and Y among all records in the table at any point in time. Using MX and MY, new records are inserted in the table 128 times with X and Y values being MX + 1, 2*MY + 1 respectively. It may be noted that each time after the insertion, values of MX and MY change.
What will be the output of the following SQL query after the steps mentioned above are carried out?
SELECT Y FROM T WHERE X=7;
Suppliers(sid : integer, sname : string, city : string, street : string)
Parts(pid : integer, pname : string, color : string)
Catalog(sid : integer, pid : integer, cost : real)
Consider the following relational query on the above database:SELECT S.sname
FROM Suppliers S
WHERE S.sid NOT IN
(SELECT C.sid
FROM Catalog C
WHERE C.pid NOT IN
(SELECT P.pid
FROM Parts P
WHERE P.color<> 'blue'))
Assume that relations corresponding to the above schema are not empty. Which one of the following is the correct interpretation of the above query?