DBi202 09

QN=18 (8537) What is a "join"?

• a. 'join' used to connect two or more tables logically with or without common field(s) a

• b. 'join' used to connect two or more tables logically with common field(s)

• c. 'join' used to connect two or more tables logically without common field(s)

• d. 'join' used to connect two or more tables logically with aliases

When join R and S, we want to display all the records in R we must use:

• a. LEFT OUTER JOIN a

• b. RIGHT OUTER JOIN

• c. INNER JOIN

• d. None of the others

Given relations R(A,B) and S(B,C,D). The result of natural join of the relations R and S has

• a. Only attribute B

• b. Only two attributes R.B and S.B

• c. Attributes A, B, C, D

• d. None of the others

Relation R(x,y) currently consists of only one tuple (NULL, NULL). Which of the following queries will produce a nonempty output? That is, at least one tuple will be produced, although the tuple(s) may have NULL's.

• a. SELECT * FROM R WHERE x IS NULL

• b. SELECT * FROM R WHERE x = NULL

• c. SELECT * FROM R WHERE x = y

• d. SELECT * FROM R WHERE x <> 10

(TRUE AND NULL) returns: ???

• a. NULL

• b. TRUE

• c. FALSE

• d. None of the others

Choose the in-correct statement:

• a. In SQL Server, every DML operation is a transaction regardless of whether it has a BEGIN TRANSACTION or not

• b. COMMITTING a transaction makes permanent the changes resulting from all SQL statements in the transaction

• c. ROLLING back a transaction rejects any of the changes resulting from the SQL statements in the transaction

• d. When the sequence of tasks is complete, the SAVE POINT closes the transaction

QN=43 (8610) In order to modify or delete an existing constraint, it is necessary that:

• a. the constraint has a name

• b. the constraint has an ID

• c. the constraint has some attributes

QN=37 (8611) Look at the following tables and then choose the correct statment:

ARTISTS
Airtist_id Airtist_Name
-----------------------------------
1 Bono
2 Cher

ALBUM
artist_id Album_name
------------------------------------
3 Eat the rich

• a. The above picture is an example of a database that has not enforced referential integrity

• b. The above picture is an example of a database that has not enforced entity integrity

• c. The above picture is an example of a database that has not enforced domain integrity

• d. All of the others

QN=33 (8576) The IN SQL keyword

• a. Is used with the DISTINCT SQL keyword only

• b. Is used with the INSERT SQL keyword only

• c. Determines if a value
  any of the values in a list or a sub-query

• d. Defines the tables we are selecting or deleting data from

Choose a right answer.

• [A]
  A SOL environment is the framework under which data may exist and SQL operations on data may be executed

• [B]
  All of the others

• [C]
  Within a SQL environment are two special kinds of processes: SQL clients and SQL servers.

• [D]
  A SQL environment is a DBMS running at some installation.