Quiz Discussion

Which of the following is a legal expression in SQL?

• 1]

  SELECT NULL FROM EMPLOYEE;

   

• 2]

  SELECT NAME FROM EMPLOYEE;

   

• 3]

  SELECT NAME FROM EMPLOYEE WHERE SALARY = NULL;

   

• 4]

  None of the above

   

Which of the following is a valid SQL type?

• 1]

  CHARACTER

• 2]

  NUMERIC

• 3]

  FLOAT

• 4]

  All of the above

Which of the following is an SQL trigger supported by Oracle?

• 1]

  BEFORE

• 2]

  AFTER

• 3]

  INSTEAD OF

• 4]

  All of the above

The statement in SQL which allows changing the definition of a table is

• 1]

  Alter

• 2]

  Update

• 3]

  Create

• 4]

  Select

What SQL structure is used to limit column values of a table?

• 1]

  The LIMIT constraint

• 2]

  The CHECK constraint

• 3]

  The VALUE constraint

• 4]

  None of the above

Which one of the following is not true for a view

• 1]

  View is derived from other tables

• 2]

  View is a virtual table

• 3]

  A view definition is permanently stored as part of the database

• 4]

  View never contains derived columns

Which of the following is correct

• 1]

  a SQL query automatically eliminates duplicates

• 2]

  SQL permits attribute names to be repeated in the same relation

• 3]

  a SQL query will not work if there are no indexes on the relations

• 4]

  None of these

A report generator is used to

• 1]

  update files

• 2]

  print files on paper

• 3]

  data entry

• 4]

  delete files

‘AS’ clause is used in SQL for

• 1]

  Selection operation

• 2]

  Rename operation

• 3]

  Join operation

• 4]

  Projection operation

Which of the following is an advantage of view?

• 1]

  Data security

• 2]

  Derived columns

• 3]

  Hiding of complex queries

• 4]

  All of the above