Quiz Discussion

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

The ______ clause allows us to select only those rows in the result relation of the ____ clause that satisfy a specified predicate.

• 1]

  Where, from

• 2]

  From, select

• 3]

  Select, from

• 4]

  From, where

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

’_____’ matches any string of ______ three characters. ’_____%’ matches any string of at ______ three characters.

• 1]

  Atleast, Exactly

• 2]

  Exactly, Atleast

• 3]

  Atleast, All

• 4]

  All, Exactly

Department (dept name, building, budget) and Employee (employee_id, name, dept name, salary)
Here the dept_name attribute appears in both the relations. Here using common attributes in relation schema is one way of relating ___________ relations.

• 1]

  Attributes of common

• 2]

  Tuple of common

• 3]

  Tuple of distinct

• 4]

  Attributes of distinct

A ________ is a pictorial depiction of the schema of a database that shows the relations in the database, their attributes, and primary keys and foreign keys.

• 1]

  Schema diagram

• 2]

  Relational algebra

• 3]

  Database diagram

• 4]

  Schema flow

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

For each attribute of a relation, there is a set of permitted values, called the ________ of that attribute.

• 1]

  Domain

• 2]

  Relation

• 3]

  Set

• 4]

  Schema

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

• 1]

  Union

• 2]

  Join

• 3]

  Product

• 4]

  Intersect