Quiz Discussion

The result which the operation contains all pairs of tuples from the two relations, regardless of whether their attribute values match.

• 1]

  Join

• 2]

  Cartesian product

• 3]

  Intersection

• 4]

  Set difference

SELECT * FROM employee WHERE dept_name="Comp Sci";

In the SQL given above there is an error . Identify the error.

• 1]

  Dept_name

• 2]

  Employee

• 3]

  “Comp Sci”

• 4]

  From

Student(ID, name, dept name, tot_cred)
In this query which attributes form the primary key?

• 1]

  Name

• 2]

  Dept

• 3]

  Tot_cred

• 4]

  ID

The most commonly used operation in relational algebra for projecting a set of tuple from a relation is

• 1]

  Join

• 2]

  Projection

• 3]

  Select

• 4]

  Union

SELECT name
FROM instructor
WHERE salary <= 100000 AND salary >= 90000;

This query can be replaced by which of the following ?

• 1]

  SELECT name
  FROM instructor
  WHERE salary BETWEEN 90000 AND 100000;

   

• 2]

  SELECT name
  FROM employee
  WHERE salary <= 90000 AND salary>=100000;

   

• 3]

  SELECT name
  FROM employee
  WHERE salary BETWEEN 90000 AND 100000;

   

• 4]

  SELECT name
  FROM instructor
  WHERE salary BETWEEN 100000 AND 90000;

   

In SQL the spaces at the end of the string are removed by _______ function.

• 1]

  Upper

• 2]

  String

• 3]

  Trim

• 4]

  Lower

The term _______ is used to refer to a row.

• 1]

  Attribute

• 2]

  Tuple

• 3]

  Field

• 4]

  Instance

A relational database consists of a collection of

• 1]

  Tables

• 2]

  Fields

• 3]

  Records

• 4]

  Keys

The _______operation performs a set union of two “similarly structured” tables

• 1]

  Union

• 2]

  Join

• 3]

  Product

• 4]

  Intersect

SELECT *
FROM instructor
ORDER BY salary ____, name ___;

To display the salary from greater to smaller and name in ascending order which of the following options should be used?

• 1]

  Ascending, Descending

• 2]

  Asc, Desc

• 3]

  Desc, Asc

• 4]

  Descending, Ascending