Quiz Discussion

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

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 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 valid SQL type?

• 1]

  CHARACTER

• 2]

  NUMERIC

• 3]

  FLOAT

• 4]

  All of the above

Count function in SQL returns the number of

• 1]

  Values

• 2]

  Distinct values

• 3]

  Groups

• 4]

  Columns

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

• 1]

  UPDATE

• 2]

  DROP

• 3]

  ALTER

• 4]

  DELETE

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

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

‘AS’ clause is used in SQL for

• 1]

  Selection operation

• 2]

  Rename operation

• 3]

  Join operation

• 4]

  Projection operation

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