Quiz Discussion

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

‘AS’ clause is used in SQL for

• 1]

  Selection operation

• 2]

  Rename operation

• 3]

  Join operation

• 4]

  Projection operation

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

   

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

The language which has recently become the defacto standard for interfacing application programs with relational database system is

• 1]

  Oracle

• 2]

  SQL

• 3]

  DBase

• 4]

  4GL

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

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

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

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