Tag: databases

Questions Related to databases

How many columns are presented after executing this query:SELECT address1||','||address2||','||address2 "Adress" FROM employee;
technology databases

  1. 1

  2. 2

  3. 3

  4. 0

  5. 4

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Correct Option: A

Which Oracle access method is the fastest way for Oracle to retrieve a single row?
technology databases

  1. Primary key access

  2. Access via unique index

  3. Table access by ROWID

  4. Full table scan

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Correct Option: C

To produce a meaningful result set without any cartesian products, what is the minimum number of conditions that should appear in the WHERE clause of a four-table join?

technology databases

  1. 8

  2. 2

  3. 3

  4. 4

  5. 5

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Correct Option: C

Assuming today is Monday, 10 July 2000, what is returned by this statement: SELECT to_char(NEXT_DAY(sysdate, 'MONDAY'), 'DD-MON-RR') FROM dual;
technology databases

  1. 03-JUL-00

  2. 10-JUL-00

  3. 12-JUL-00

  4. 11-JUL-00

  5. 17-JUL-00

Show answer
Correct Option: E
Explanation:

To solve this question, the user needs to understand the function of each element of the SQL statement and how it affects the output.

The SQL statement is selecting a date and formatting it according to the given format string. Specifically:

  • sysdate returns the current date and time.
  • NEXT_DAY(sysdate, 'MONDAY') returns the next occurrence of the day specified as the second argument, after the current date and time (sysdate). In this case, it returns the next Monday after 10 July 2000, which is 17 July 2000.
  • to_char() converts the resulting date into a string using the format specified as the second argument. In this case, the format is 'DD-MON-RR', which returns the day of the month (DD), the abbreviated month name (MON), and the 2-digit year (RR).

Therefore, the correct answer is E. 17-JUL-00, as the SQL statement returns the formatted date of the next Monday after 10 July 2000, which is 17 July 2000.

Which character is used to continue a statement in SQL*Plus?
technology databases

  1. *

  2. /

  3. -

  4. @

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Correct Option: C

When a user creates an object without a TABLESPACE clause, where will Oracle store the segment?

technology databases

  1. System tablespace

  2. Users tablespace

  3. Default tablespace for the user

  4. Oracle will give an error

  5. Undefined

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Correct Option: C

The primary key on table EMP is the EMPNO column. Which of the following statements will not use the associated index on EMPNO?
technology databases

  1. select * from EMP where nvl(EMPNO, '00000') = '59384'

  2. select * from EMP where EMPNO = '59384'

  3. select EMPNO, LASTNAME from EMP where EMPNO = '59384'

  4. select 1 from EMP where EMPNO = '59834'

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Correct Option: A

Which character function can be used to return a specified portion of a character string

technology databases

  1. INSTR

  2. SUBSTRING

  3. SUBSTR

  4. POS

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Correct Option: C

Which command will delete all data from a table and will not write to the rollback segment?

technology databases

  1. DROP

  2. DELETE

  3. CASCADE

  4. TRUNCATE

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Correct Option: D

Which of the following can be a valid column name
technology databases

  1. Column

  2. 1966_Invoices

  3. Catch_#22

  4. #Invoices

  5. None of the above

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Correct Option: D