Quiz Discussion

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

The term attribute refers to a ___________ of a table.

• 1]

  Record

• 2]

  Column

• 3]

  Tuple

• 4]

  Key

The _______ operator takes the results of two queries and returns only rows that appear in both result sets.

• 1]

  Union

• 2]

  Intersect

• 3]

  Difference

• 4]

  Projection

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

A domain is atomic if elements of the domain are considered to be ____________ units.

• 1]

  Different

• 2]

  Indivisbile

• 3]

  Constant

• 4]

  Divisible

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

A relational database consists of a collection of

• 1]

  Tables

• 2]

  Fields

• 3]

  Records

• 4]

  Keys

The tuples of the relations can be of ________ order.

• 1]

  Any

• 2]

  Same

• 3]

  Sorted

• 4]

  Constant

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

Database __________ which is the logical design of the database, and the database _______ which is a snapshot of the data in the database at a given instant in time.

• 1]

  Instance, Schema

• 2]

  Relation, Schema

• 3]

  Relation, Domain

• 4]

  Schema, Instance