Quiz Discussion

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

Which of the following is a comparison operator in SQL?

• 1]

  =

• 2]

  LIKE

• 3]

  BETWEEN

• 4]

  All of the above

A reason for using an SQL view to hide columns is

• 1]

  to simplify a result only

• 2]

  to prevent the display of sensitive data only

• 3]

  to accomplish both of the above

• 4]

  None of the above

Which is NOT one of the most common types of SQL CHECK constraints?

• 1]

  System date

• 2]

  Range checks

• 3]

  Lists of values

• 4]

  Comparing one column value to another within the same table

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

Which of the following is a valid SQL type?

• 1]

  CHARACTER

• 2]

  NUMERIC

• 3]

  FLOAT

• 4]

  All of the above

‘AS’ clause is used in SQL for

• 1]

  Selection operation

• 2]

  Rename operation

• 3]

  Join operation

• 4]

  Projection operation

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

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