Tag: databases

Questions Related to databases

In an Oracle Database, Locks are critical

technology databases

  1. True

  2. False

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Correct Option: B

Character values are case insensitive

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  1. True

  2. False

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Correct Option: B

Duplicate values are eliminated by which keyword
technology databases

  1. Duplicate

  2. Distinct

  3. Remove

  4. Delete

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Correct Option: B

The two types of subqueries are:
technology databases

  1. Single-row subquery, Double-row subquery

  2. Double-row subquery, Multiple-row subquery

  3. Multiple-row subquery

  4. Single-row subquery and Multiple subquery

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Correct Option: D

Single-row subquery returns:

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  1. Only one row

  2. Two rows

  3. Zero rows

  4. There is no such subquery

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Correct Option: A

Which of the following is not a multiple-row operator?
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  1. IN

  2. OF

  3. ALL

  4. ANY

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Correct Option: B

Which operator compares a value to every value returned by a subquery?

technology databases

  1. IN

  2. OF

  3. ALL

  4. ANY

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Correct Option: C

A DML statement is executed when you
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  1. Add new rows to a table

  2. Modify existing rows of a table

  3. Remove existing rows from a table

  4. All of the above

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Correct Option: D

The right syntax insert a row into a table is
technology databases

  1. Insert to table tablename (….);

  2. Insert into table tablename (….);

  3. Insert into table tablename values (…..);

  4. Any one of the above

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Correct Option: C

Arithmetic expressions containing a null value evaluate to null.
technology databases

  1. True

  2. False

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Correct Option: B
Explanation:

To solve this question, the user needs to know what a null value is and how arithmetic expressions are evaluated.

A null value is a value that represents an absence of a value or an unknown value. In arithmetic expressions, null values can occur when a value is missing or undefined.

Now, let's go through each option and explain why it is right or wrong:

A. True: This option is incorrect. Arithmetic expressions containing a null value do not necessarily evaluate to null. The actual result depends on the specific operation being performed and the other values in the expression.

B. False: This option is correct. Arithmetic expressions containing a null value do not necessarily evaluate to null. The actual result depends on the specific operation being performed and the other values in the expression.

The Answer is: B