Tag: databases

Questions Related to databases

Which of the below is a part of Data Control Language?
technology databases

  1. SELECT

  2. DENY

  3. APPLY

  4. UPDATE

  5. None of the above

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Correct Option: B

We cannot decide if a server is a linked server by using sys.servers catalog view. True or False?

technology databases

  1. True

  2. False

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Correct Option: B

In the Table employee_Details there are two columns: Employee_Id-Integer[10] and Employee_Name-Char[10],The following select query Select distinct(Employee_Name) from employee_Details where Employee_Id='1232' fails due to:
technology databases

  1. The field mentioned in the where clause should be one of the columns selected

  2. The distinct function can not be used on a field of type Char

  3. The Integer value mentioned in the where clause should not be enclosed by quotes since it is of integer type.

  4. none of the above.

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Correct Option: C

The ORDER BY keyword sort the records in descending order by default.

technology databases

  1. True

  2. False

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Correct Option: B

fill up:A LEFT JOIN Return all rows from the _________ table, even if there are no matches in the __________ table

technology databases

  1. left,right

  2. right,left

  3. left,left

  4. right,right

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Correct Option: A

AI Explanation

To answer this question, you need to understand the concept of a LEFT JOIN in SQL.

A LEFT JOIN returns all rows from the left table, even if there are no matches in the right table.

Let's go through each option to understand why it is correct or incorrect:

Option A) left, right - This option is correct because a LEFT JOIN returns all rows from the left table, even if there are no matches in the right table. Option B) right, left - This option is incorrect because a RIGHT JOIN returns all rows from the right table, even if there are no matches in the left table. Option C) left, left - This option is incorrect because a LEFT JOIN returns all rows from the left table, even if there are no matches in the right table. Option D) right, right - This option is incorrect because a RIGHT JOIN returns all rows from the right table, even if there are no matches in the left table.

The correct answer is Option A) left, right. This option is correct because a LEFT JOIN returns all rows from the left table, even if there are no matches in the right table.

Fill Up: The UNION operator selects only distinct values by default. To allow duplicate values, use __________

technology databases

  1. UNION ENTIRE

  2. FULL UNION

  3. UNION ALL

  4. none of the above

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Correct Option: C

The following query fails. Select employee_name,employee_id,count() from employee_Details group by employee_id where count()>2; The right format is:
technology databases

  1. Select employee_name,count() from employee_Details group by employee_id where count()>2;

  2. Select employee_name,employee_id,count() from employee_Details group by employee_id having count()>2;

  3. Select employee_name,employee_id,count() from employee_Details order by employee_id where count()>2;

  4. NONE of THE ABOVE

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Correct Option: B

Select * from employee_Details with ur; in the follwoing query UR stands for:
technology databases

  1. Under Read

  2. neither a,c or d

  3. Uncommitted Read

  4. Uncommitted Ride

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Correct Option: C

An application program containing query with UR
technology databases

  1. can read data that has been changed and committed.

  2. can read data that has been changed but is not yet committed.

  3. both a and b

  4. neither a or b

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Correct Option: C

Select the right syntax to delete all the rows from the table employee_Details but retain the table :
technology databases

  1. delete * from employee_Details

  2. delete from employee_Details

  3. truncate table employee_Details

  4. drop table employee_Details

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Correct Option: B,C