Tag: databases

Questions Related to databases

The o/p of the below query.. select 1/0 from dual ;
technology databases

  1. Error: Syntax error

  2. INFINITY

  3. NULL

  4. 0

  5. Error: divisor is equal to zero

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Correct Option: E

The o/p of the below query.. select 0/1 from dual group by dummy;
technology databases

  1. 0

  2. 1

  3. NULL

  4. Error: divisor is equal to zero

  5. Error: Not a GROUP BY clause

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Correct Option: A

select dummy,count(1) from dual group by dummy; O/p:
technology databases

  1. Error: Not a GROUP BY Clause

  2. X,0

  3. X,1

  4. Two rows of value (X,0) & (X,1)

  5. No rows returned

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Correct Option: C

select max(5)*min(5)/avg(5) from dual group by dummy; o/p:
technology databases

  1. 5

  2. 25

  3. 125

  4. 1

  5. Error: Syntax error

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Correct Option: A

select avg(dummy) from dual; o/p:
technology databases

  1. Error: Invalid Number

  2. Error: Invalid Character

  3. 0

  4. 1

  5. Error: divisor is equal to zero

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Correct Option: A

select min(dummy) from dual union all select max(dummy) from dual group by dummy; o/p: ??
technology databases

  1. Two rows of value X and X

  2. Error: SQL command not properly ended

  3. Error: Not a proper GROUP BY clause

  4. X

  5. NULL

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Correct Option: A

select min(dummy) from dual order by dummy union all select max(dummy) from dual; O/p:
technology databases

  1. X

  2. Two rows of value X and X

  3. Error: Not a proper ORDER BY clause

  4. Error: SQL command not properly ended

  5. 1

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Correct Option: D

select connect from dual; o/p:
technology databases

  1. Error: Missing expression

  2. connect

  3. It will show connection string name

  4. NULL

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Correct Option: A

select rowid from dual;
technology databases

  1. It will show one row but no no column,no value,not even NULL value

  2. 1

  3. 0

  4. NULL

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Correct Option: A

select rownum from dual;
technology databases

  1. It will show one row but no no column,no value-,not even NULL value

  2. NULL

  3. 0

  4. 1

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Correct Option: D