Null Values Operations MCQ

Test your knowledge with important Null Values Operations MCQ and their applications. These MCQs are beneficial for competitive exams too. Explore 30 + more Null Values Operations MCQs at Bissoy

• The result of _____unknown is unknown.
  ক

  Xor

  খ

  Or

  গ

  And

  ঘ

  Not
• The primary key must be
  ক

  Unique

  খ

  Not null

  গ

  Both Unique and Not null

  ঘ

  Either Unique or Not null
• Using the ______ clause retains only one copy of such identical tuples.
  ক

  Null

  খ

  Unique

  গ

  Not null

  ঘ

  Distinct
• In an employee table to include the attributes whose value always have some value which of the following constraint must be used?
  ক

  Null

  খ

  Not null

  গ

  Unique

  ঘ

  Distinct
• The predicate in a where clause can involve Boolean operations such as and. The result of true and unknown is_______ false and unknown is _____ while unknown and unknown is _____
  ক

  Unknown, unknown, false

  খ

  True, false, unknown

  গ

  True, unknown, unknown

  ঘ

  Unknown, false, unknown
• If the attribute phone number is included in the relation all the values need not be entered into the phone number column. This type of entry is given as
  ক

  0

  খ

  –

  গ

  Null

  ঘ

  Empty space
• A _____ indicates an absent value that may exist but be unknown or that may not exist at all.
  ক

  Empty tuple

  খ

  New value

  গ

  Null value

  ঘ

  Old value