Recent questions tagged sql / GATE Overflow for GATE CSE

0 votes

0 answers

331

repeted values in Relation Table
I want to know as we know codd's rule says that no two tuples in a relation should be same. i.e we can not have 2 tuples with same values in clm feilds. now to maintain these constraints, we choose to have some key over the relation ... having mutiset values, (as there are no keys present), how Dbms do indexing to retrive records? someone help me on this pls.

I want to know as we know codd's rule says that no two tuples in a relation should be same. i.e we can not have 2 tuples with same values in clm feilds. now to maintain t...

mohit chawla

1.4k views

mohit chawla asked Jan 25, 2017

1 votes

2 answers

332

Test by Bikram | Mock GATE | Test 2 | Question: 55
Consider the set of relations for the given $SQL$ query: EMP (eno, ename) DEPT (dno,dname) WORKS_IN (eno,dno) Where primary keys of the relations are eno, dno in $EMP$ table and $DEPT$ ... all departments The eno's of employees working in 2 (or) more departments The eno's of employees not working in any department

Consider the set of relations for the given $SQL$ query:EMP (eno, ename) DEPT (dno,dname) WORKS_IN (eno,dno)Where primary keys of the relations are eno, dno in $EMP$ tabl...

Bikram

297 views

Bikram asked Jan 24, 2017

1 votes

1 answer

333

MadeEasy Subject Test: Databases - Sql
Correct Ans and how?

Correct Ans and how?

Jason_Roy

412 views

Jason_Roy asked Jan 21, 2017

1 votes

1 answer

334

ace 2017 test series
How will this query execute? Q1: Select pno from project Q2: select pno from works where employee.eno=works.eno Now Q1 except Q2 will all projects which do not have an employee working on it. So the outer query should give: All employees who are working on some project. But answer is: Employees working on all projects.

How will this query execute?Q1: Select pno from projectQ2: select pno from works where employee.eno=works.enoNow Q1 except Q2 will all projects which do not have an emplo...

Purple

430 views

Purple asked Jan 19, 2017

2 votes

2 answers

335

SQL Query
The Given Answer is C) , my doubt is can PassportNo take NULL values as it is defined as UNIQUE ?

The Given Answer is C) , my doubt is can PassportNo take NULL values as it is defined as UNIQUE ?

Harsh181996

666 views

Harsh181996 asked Jan 17, 2017

1 votes

2 answers

336

Test by Bikram | Mock GATE | Test 1 | Question: 19
Consider the following $SQ$L query: With max_balance(value) as Select max(balance) from account; The result of executing the above query is: $A$ temporary table is created with the name $max$_$balance$ $A$ temporary view is created with ... view is created with the name $max$_$balance$ $A$ permanent table is created with the name $max$_$balance$

Consider the following $SQ$L query:With max_balance(value) as Select max(balance) from account;The result of executing the above query is:$A$ temporary table is created w...

Bikram

797 views

Bikram asked Jan 16, 2017

0 votes

0 answers

337

MadeEasy Subject Test: Databases - Sql
i think here in Q2 >>> query write in wrong way.........here missing some brackets ??

i think here in Q2 >> query write in wrong way.........here missing some brackets ??

Hradesh patel

232 views

Hradesh patel asked Jan 12, 2017

6 votes

0 answers

338

SQL query
Plz explain both queries!

Plz explain both queries!

Lokesh .

1.3k views

Lokesh . asked Jan 12, 2017

1 votes

0 answers

339

SQL DBMS

shubhamdarokar

824 views

shubhamdarokar asked Jan 10, 2017

1 votes

2 answers

340

Virtual Gate Test Series: Databases - Sql Query
Consider the following instances $R.$ A 1 2 3 4 B Null 1 2 2 The number of tuples returned by the following $\text{SQL query}$ is$?$ $>$select $*$ from $R$ as $R_{1}$ where not exists$($select $*$ from $R$ where $B = R_{1}.A)$

Consider the following instances $R.$A1234BNull122The number of tuples returned by the following $\text{SQL query}$ is$?$$>$select $*$ from $R$ as $R_{1}$ where not exist...

Purple

508 views

Purple asked Jan 9, 2017

1 votes

1 answer

341

MadeEasy Subject Test: Databases - Sql
Please help,not able to decode this query

Please help,not able to decode this query

rahul sharma 5

1.1k views

rahul sharma 5 asked Jan 9, 2017

0 votes

1 answer

342

Virtual Gate Test Series: Databases - Sql query

Jason GATE

466 views

Jason GATE asked Jan 8, 2017

0 votes

1 answer

343

MadeEasy Subject Test: Databases - Sql
Please explain how??

Please explain how??

Lucky sunda

419 views

Lucky sunda asked Jan 7, 2017

1 votes

1 answer

344

MadeEasy Subject Test: Databases - Sql

vaishali jhalani

376 views

vaishali jhalani asked Jan 7, 2017

3 votes

1 answer

345

[DBMS] Position of Nulls using order by clause
I have a small doubt on order by clause usgae.I need to understand the position of null in case i order by ascending order or desending order,I referred http://docs.oracle.com/javadb/10.8.3.0/ref/rrefsqlj13658.html,whichsays ... order. But i tried some examples at http://www.w3schools.com/sql/sql_update.asp,which gave me opposite result.Please clarify

I have a small doubt on order by clause usgae.I need to understand the position of null in case i order by ascending order or desending order,I referred http://docs.orac...

rahul sharma 5

414 views

rahul sharma 5 asked Jan 6, 2017

2 votes

1 answer

346

SQL-doubt
1. Can WHERE clause be used with aggregate functions ? 2. DISTINCT operates on a single column. DISTINCT for multiple columns is not supported. [T/F]

1. Can WHERE clause be used with aggregate functions ?2. DISTINCT operates on a single column. DISTINCT for multiple columns is not supported. [T/F]

thor

367 views

thor asked Jan 2, 2017

3 votes

2 answers

347

SQL <=ALL Query
select studentid, studentname from student where birthyear <=ALL( select birthyear from student); Returns detail of the youngest student Returns detail of oldest student Should not the answer be 2) ?

select studentid, studentname from student where birthyear <=ALL( select birthyear from student);Returns detail of the youngest studentReturns detail of oldest studentSho...

yg92

624 views

yg92 asked Dec 31, 2016

3 votes

1 answer

348

Ace Test Series: Databases - Sql

chaser

503 views

chaser asked Dec 30, 2016

1 votes

2 answers

349

MadeEasyTest #Query

Turning Turing

413 views

Turning Turing asked Dec 27, 2016

1 votes

1 answer

350

dbms sql
Which of the following query will give name of the employee who is earning maximum salary? 1. Select name from emp where sal=(Select max(sal) from emp); 2. Select name from emp where sal>=all(Select max(sal) from emp); 3. Both a and b are correct queries 4. Both a and b are incorrect queries

Which of the following query will give name of the employee who is earning maximum salary?1. Select name from emp where sal=(Select max(sal) from emp);2. Select name from...

focus _GATE

313 views

focus _GATE asked Dec 26, 2016

5 votes

2 answers

351

Working of ANY and ALL with empty set
create table stud(id int, grade varchar(20)); insert into stud values(1, 'A'); insert into stud values(2, 'A'); insert into stud values(3, 'B'); insert into stud values(4, 'B'); // Working of ALL ... rerturns NOTHING and NOT a null. Is that an empty set? How is ANY and ALL deciding their output with respect to empty set?

create table stud(id int, grade varchar(20)); insert into stud values(1, 'A'); insert into stud values(2, 'A'); insert into stud values(3, 'B'); insert into stud values(4...

yg92

2.0k views

yg92 asked Dec 21, 2016

5 votes

3 answers

352

GATE CSE 1988 | Question: 12iv
Select SNAME from S Where SNOin (select SNO from SP where PNOin (select PNO from P Where COLOUR='BLUE')) What relations are being used in the above SQL query? Given at least two attributes of each of these relations.

Select SNAME from S Where SNOin (select SNO from SP where PNOin (select PNO from P Where COLOUR='BLUE'))What relations are being used in the above SQL query? Given at lea...

go_editor

1.4k views

go_editor asked Dec 20, 2016

10 votes

3 answers

353

GATE CSE 1988 | Question: 12iii
Describe the relational algebraic expression giving the relation returned by the following SQL query. Select SNAME from S Where SNOin (select SNO from SP where PNOin (select PNO from P Where COLOUR='BLUE'))

Describe the relational algebraic expression giving the relation returned by the following SQL query.Select SNAME from S Where SNOin (select SNO from SP where PNOin (sele...

go_editor

2.1k views

go_editor asked Dec 20, 2016

0 votes

0 answers

354

SQL Query || 2
Student (Sid,gender,marks,branch) Query: Retrieve Sid's with highest marks in their respective branch -- using RA logic SELECT Sid FROM Student EXCEPT SELECT Sid FROM Student S1,Student S2 WHERE S1.marks < S2.marks AND S1.branch = S2.branch And -- ... = T.branch AND marks = mrks Please suggest any other method to write this query in SQl , using different logic or construct.

Student (Sid,gender,marks,branch)Query: Retrieve Sid's with highest marks in their respective branch using RA logic SELECT Sid FROM Student EXCEPT SELECT Sid FROM Studen...

dd

5.3k views

dd asked Dec 18, 2016

2 votes

2 answers

355

SQL query || 1
Student (Sid,gender,marks,branch) Query: Retrieve Sid's who scored the highest mark? SELECT SID FROM Student EXCEPT SELECT T1.Sid FROM Student T1,Student T2 WHERE T1.marks < T2.marks What are other possible correct variation equal to this query in SQL ?

Student (Sid,gender,marks,branch)Query: Retrieve Sid's who scored the highest mark?SELECT SID FROM Student EXCEPT SELECT T1.Sid FROM Student T1,Student T2 WHERE T1.marks ...

dd

2.3k views

dd asked Dec 17, 2016

0 votes

0 answers

356

SQL HAVING Clause
Can Anyone Explain how Query 28 works with example.

Can Anyone Explain how Query 28 works with example.

Beyonder

731 views

Beyonder asked Nov 30, 2016

23 votes

1 answer

357

GATE CSE 1990 | Question: 10-a
Consider the following relational database: employees (eno, ename, address, basic-salary) projects (pno, pname, nos-of-staffs-allotted) working (pno, eno, pjob) The queries regarding data in the above database are formulated below in SQL. ... FROM projects)) SELECT pname FROM projects WHERE pno IN (SELECT pno FROM projects MINUS SELECT DISTINCT pno FROM working);

Consider the following relational database:employees (eno, ename, address, basic-salary)projects (pno, pname, nos-of-staffs-allotted)working (pno, eno, pjob)The queries r...

makhdoom ghaya

2.9k views

makhdoom ghaya asked Nov 24, 2016

1 votes

2 answers

358

Output of SQL query
The innermost query select those projects which have employees working under it; hence NOT EXISITS will select those Pid's that do not have any employees working under it. The second innermost query will select those Pid's which doesn't have any ... . Hence the outermost query will select 2 also along with other pid's. Doesn't that make option c correct?

The innermost query select those projects which have employees working under it; hence NOT EXISITS will select those Pid's that do not have any employees working under it...

prasitamukherjee

605 views

prasitamukherjee asked Nov 22, 2016

3 votes

1 answer

359

MadeEasy Test Series: Databases - Sql
i think neither of the queries can implement given specification. plz confirm!

i think neither of the queries can implement given specification. plz confirm!

Anusha Motamarri

653 views

Anusha Motamarri asked Nov 21, 2016

3 votes

2 answers

360

Predict the output of given SQL query
Tables are : COUNTRY (CODE, NAME) and MEMBER (ORGANIZATION, COUNTRY_code). primary keys are in blod letters and foreign key is in italics. SELECT COUNTRY.name FROM COUNTRY JOIN member ON COUNTRY.code= member.COUNTRY_code WHERE member. ... are members of one or more organisations. 4. List the names of countries which are members of all organisations.

Tables are : COUNTRY (CODE, NAME) and MEMBER (ORGANIZATION, COUNTRY_code). primary keys are in blod letters and foreign key is in italics.SELECT COUNTRY.nameFROM COUNTRYJ...

sh!va

1.9k views

sh!va asked Nov 14, 2016

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title	title:apple
content	content:apple
exclude	-tag:apple
force match	+apple
views	views:100
score	score:10
answers	answers:2
is accepted	isaccepted:true
is closed	isclosed:true