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

   

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

• 1]

  UPDATE

• 2]

  DROP

• 3]

  ALTER

• 4]

  DELETE

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

What is an advantage of placing computations in SQL views

• 1]

  To save users from having to write an expression

• 2]

  To ensure that the results are consistent

• 3]

  To accomplish both of the above

• 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 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

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

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 an advantage of view?

• 1]

  Data security

• 2]

  Derived columns

• 3]

  Hiding of complex queries

• 4]

  All of the above