Explore topic-wise MCQs in Database.

This section includes 37 Mcqs, each offering curated multiple-choice questions to sharpen your Database knowledge and support exam preparation. Choose a topic below to get started.

1.

Because of the need for extensive knowledge of SQL, many database developers choose to automate the redesign process.

A. 1
B.
Answer» C.
Discussion
2.

The NOT EXISTS keyword will be true if any row in the subquery meets the condition.

A. 1
B.
Answer» C.
Discussion
3.

The data model produced from the reverse engineering process does not include intersection table data.

A. 1
B.
Answer» C.
Discussion
4.

It is not easy to build a database correctly the first time.

A. 1
B.
Answer» B.
Discussion
5.

Adding null columns to a table is straightforward.

A. 1
B.
Answer» B.
Discussion
6.

The EXISTS keyword will be true if any row in the subquery meets the condition.

A. 1
B.
Answer» B.
Discussion
7.

The data model produced from the reverse engineering process is a true logical model.

A. 1
B.
Answer» C.
Discussion
8.

If a database is built correctly the first time, it will not have to be redesigned.

A. 1
B.
Answer» C.
Discussion
9.

Although creating test databases is a critical and necessary job, there are few career opportunities in this area.

A. 1
B.
Answer» C.
Discussion
10.

Reverse engineering is the process of reading a database schema and producing a data model from that schema.

A. 1
B.
Answer» B.
Discussion
11.

Typically, there should be at least two different copies of the database schema used in the redesign process.

A. 1
B.
Answer» C.
Discussion
12.

Dependency graphs are diagrams that consist of nodes and arcs that show the dependencies of a database.

A. 1
B.
Answer» B.
Discussion
13.

How many copies of the database schema are typically used in the redesign process?

A. One
B. Two
C. Three
D. Four
Answer» D. Four
Discussion
14.

To drop a column that is used as a foreign key, first:

A. drop the primary key.
B. drop the table containing the foreign key..
C. drop the foreign key constraint.
D. All of the above must be done.
Answer» D. All of the above must be done.
Discussion
15.

Information systems and organizations do not just influence each other; they create each other.

A. 1
B.
C. 1
D.
Answer» B.
Discussion
16.

A regular subquery is processed from the bottom up.

A. 1
B.
Answer» B.
Discussion
17.

A tool that can help designers understand the dependencies of database structures is a:

A. dependency graph.
B. data model.
C. graphical display.
D. None of the above is correct.
Answer» B. data model.
Discussion
18.

Which is not true of a correlated subquery?

A. EXISTS/NOT EXISTS is a form of a correlated subquery.
B. The processing of the SELECT statements is nested.
C. They can be used to verify functional dependencies.
D. They are very similar to a regular subquery.
Answer» E.
Discussion
19.

The SQL-92 command to change a table name is RENAME TABLE.

A. 1
B.
C. 1
D.
Answer» C. 1
Discussion
20.

Correlated subqueries are similar to a regular subquery.

A. 1
B.
Answer» C.
Discussion
21.

Some organizations take the stand that no application should ever employ the true name of a table.

A. 1
B.
Answer» B.
Discussion
22.

What SQL command can be used to add columns to a table?

A. MODIFY TABLE TableName ADD COLUMN ColumnName
B. MODIFY TABLE TableName ADD ColumnName
C. ALTER TABLE TableName ADD COLUMN ColumnName
D. ALTER TABLE TableName ADD ColumnName
Answer» E.
Discussion
23.

Because of the importance of making data model changes correctly, many professionals are ________ about using an automated process for database redesign.

A. optimistic
B. skeptical
C. ambivalent
D. None of the above is correct.
Answer» C. ambivalent
Discussion
24.

The use of the double NOT EXISTS can be used to find rows that do not match some specified condition.

A. 1
B.
C. 1
D.
Answer» B.
Discussion
25.

How can you find rows that do not match some specified condition?

A. EXISTS
B. Double use of NOT EXISTS
C. NOT EXISTS
D. None of the above is correct.
Answer» C. NOT EXISTS
Discussion
26.

Database redesign is especially difficult if the database has no data.

A. 1
B.
Answer» C.
Discussion
27.

A regular subquery can be processed:

A. from the top down.
B. from the bottom up.
C. by nesting.
D. None of the above is correct.
Answer» C. by nesting.
Discussion
28.

Changing cardinalities in a database is:

A. a common database design task.
B. a rare database design task, but does occur.
C. a database design task that never occurs.
D. is impossible to do, so a new database must be constructed and the data moved into it.
Answer» B. a rare database design task, but does occur.
Discussion
29.

Which of the following modifications may not succeed?

A. Changing a column data type from char to date
B. Changing a column data type from numeric to char
C. Both of the above actions should succeed.
D. Neither of the above actions will succeed.
Answer» B. Changing a column data type from numeric to char
Discussion
30.

The NOT EXISTS keyword will be true if:

A. any row in the subquery meets the condition.
B. all rows in the subquery fail the condition.
C. both of these two conditions are met.
D. neither of these two conditions is met.
Answer» C. both of these two conditions are met.
Discussion
31.

Before any changes to database structure are attempted one should first:

A. clearly understand the current structure and contents of the database only.
B. test any changes on a test database only.
C. create a complete backup of the operational database only.
D. All of the above should be done.
Answer» E.
Discussion
32.

What SQL command can be used to delete columns from a table?

A. MODIFY TABLE TableName DROP COLUMN ColumnName
B. MODIFY TABLE TableName DROP ColumnName
C. ALTER TABLE TableName DROP COLUMN ColumnName
D. ALTER TABLE TableName DROP ColumnName
Answer» D. ALTER TABLE TableName DROP ColumnName
Discussion
33.

The process of reading a database schema and producing a data model from that schema is known as:

A. data modeling.
B. database design.
C. reverse engineering.
D. None of the above is correct.
Answer» D. None of the above is correct.
Discussion
34.

The EXISTS keyword will be true if:

A. any row in the subquery meets the condition only.
B. all rows in the subquery fail the condition only.
C. both of these two conditions are met.
D. neither of these two conditions is met.
Answer» B. all rows in the subquery fail the condition only.
Discussion
35.

Which SQL-92 standard SQL command can be used to change a table name?

A. RENAME TABLE
B. CHANGE TABLE
C. ALTER TABLE
D. None of the above is correct.
Answer» E.
Discussion
36.

A correlated subquery is processed as a nested subquery.

A. 1
B.
C. 1
D.
Answer» B.
Discussion
37.

Which of the following SQL statements are helpful in database redesign?

A. Correlated subqueries only
B. EXISTS/NOT EXISTS expressions only
C. Both of the above are helpful
D. None of the above are helpful.
Answer» D. None of the above are helpful.
Discussion