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 an SQL trigger supported by Oracle?

• 1]

  BEFORE

• 2]

  AFTER

• 3]

  INSTEAD OF

• 4]

  All of the above

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

Views constructed from SQL SELECT statements that conform to the SQL-92 standard may not contain

• 1]

  GROUP BY

• 2]

  WHERE

• 3]

  ORDER BY

• 4]

  FROM

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

• 1]

  Alter

• 2]

  Update

• 3]

  Create

• 4]

  Select

To delete a particular column in a relation the command used is

• 1]

  UPDATE

• 2]

  DROP

• 3]

  ALTER

• 4]

  DELETE

Count function in SQL returns the number of

• 1]

  Values

• 2]

  Distinct values

• 3]

  Groups

• 4]

  Columns

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

The SQL ALTER statement can be used to

• 1]

  Change the table structure

• 2]

  Change the table data

• 3]

  Add rows to the table

• 4]

  Delete rows from the table

A report generator is used to

• 1]

  update files

• 2]

  print files on paper

• 3]

  data entry

• 4]

  delete files