SNHU DAD 220 TEST 2025/2026 QUESTIONS WITH
ANSWERS GRADED A+
✔✔When a table is in third normal form, which of these is true? Select one. - ✔✔All
non-key columns depend on the whole primary key and on no other columns.
✔✔You are analyzing data for a new sports stats website and have access to their
databases related to the Major League Baseball games. A coworker has created the
table Attendance, which estimates the average attendance at home games next season
for franchises in each division of the National League and the American League. -
✔✔SELECT League, Division, MAX(Average) FROM Attendance GROUP by League,
Division ORDER by League, Division
✔✔1. SELECT MIN(Year) FROM Opioid Addiction
2. SELECT MAX(Percentage) FROM Opioid Addiction
3.SELECT COUNT(*) FROM Opioid Addiction WHERE Percentage <0.04
4. SELECT AVG(Percentage) FROM Opioid Addiction - ✔✔1.2016
2. 0.066
3. 4
4. 0.039
✔✔1. SELECT CONCAT(CITY,FRANCHISNAME) FROM ATTENDANCE WHERE
GAMEPLAYERS < 35000
2. SELECT REPLACE('ST. LOUIS','ST.','SAINT')
3. SELECT SUBSTRING('ST. LOUIS',1,3)
4. SELECT CONCAT (FRANCHISENAME, CITY) FROM SUPERBOWLSTATS
WHERE GAMEPLAYER > 45000 - ✔✔1. CHICAGOMARAUDERS
2. SAINT LOUIS
3. ST
4. PACERSCLEVELAND
✔✔True or False: A logical operator always evaluates to null when one or bother
operands are null - ✔✔false
✔✔Which of these are true about null values? Select all that apply. - ✔✔A null value is
different from a zero value or an empty string. One NULL is never equal to another.
✔✔1. The wildcard character %
2. The wildcard character _
3. LIKE by default
4. LIKE followed by BINARY - ✔✔1. To match any number of characters
2. To match exactly one character
3. To conduct a case-insensitive pattern match
4. To conduct a case-sensitive pattern match
, ✔✔ fact - ✔✔related values
✔✔redundancy - ✔✔repetition of a fact
✔✔normal forms - ✔✔rules for designing tables with less redundancy
The six normal forms comprise a sequence, with each normal form allowing less
redundancy than the prior normal form.
✔✔What are the Normal Forms - ✔✔Normal forms are numbered, first normal form
through fifth normal form. An additional normal form, named Boyce-Codd normal form,
is considered an improved version of third normal form.
✔✔First normal form - ✔✔all non-key columns must depend on the primary key
✔✔What does dependence mean in an ERD? - ✔✔each instance of a dependent entity
always relates to an instance of another entity
Called: Existence dependence
✔✔What does dependence mean in a relational model? - ✔✔each value of a column
relates to at most one value of another column
Called: Functional dependence
✔✔second normal form - ✔✔all non-key columns must depend on the whole primary
key.
In other words, a non-key column cannot depend on part of a composite primary key.
✔✔Third normal form - ✔✔All non-key columns depend on the key, the whole key, and
nothing but the key.
✔✔In what situations is redundancy more acceptable? - ✔✔In a database used
primarily for reporting, changes are infrequent and redundancy is acceptable. In fact,
redundancy can be desirable in reporting databases, as processing is faster and
queries are simpler. For this reason, reporting databases may contain tables that, by
design, are not in third normal form.
✔✔Denormalization - ✔✔intentionally introducing redundancy by merging tables.
Denormalization eliminates join queries and therefore improves query performance.
ANSWERS GRADED A+
✔✔When a table is in third normal form, which of these is true? Select one. - ✔✔All
non-key columns depend on the whole primary key and on no other columns.
✔✔You are analyzing data for a new sports stats website and have access to their
databases related to the Major League Baseball games. A coworker has created the
table Attendance, which estimates the average attendance at home games next season
for franchises in each division of the National League and the American League. -
✔✔SELECT League, Division, MAX(Average) FROM Attendance GROUP by League,
Division ORDER by League, Division
✔✔1. SELECT MIN(Year) FROM Opioid Addiction
2. SELECT MAX(Percentage) FROM Opioid Addiction
3.SELECT COUNT(*) FROM Opioid Addiction WHERE Percentage <0.04
4. SELECT AVG(Percentage) FROM Opioid Addiction - ✔✔1.2016
2. 0.066
3. 4
4. 0.039
✔✔1. SELECT CONCAT(CITY,FRANCHISNAME) FROM ATTENDANCE WHERE
GAMEPLAYERS < 35000
2. SELECT REPLACE('ST. LOUIS','ST.','SAINT')
3. SELECT SUBSTRING('ST. LOUIS',1,3)
4. SELECT CONCAT (FRANCHISENAME, CITY) FROM SUPERBOWLSTATS
WHERE GAMEPLAYER > 45000 - ✔✔1. CHICAGOMARAUDERS
2. SAINT LOUIS
3. ST
4. PACERSCLEVELAND
✔✔True or False: A logical operator always evaluates to null when one or bother
operands are null - ✔✔false
✔✔Which of these are true about null values? Select all that apply. - ✔✔A null value is
different from a zero value or an empty string. One NULL is never equal to another.
✔✔1. The wildcard character %
2. The wildcard character _
3. LIKE by default
4. LIKE followed by BINARY - ✔✔1. To match any number of characters
2. To match exactly one character
3. To conduct a case-insensitive pattern match
4. To conduct a case-sensitive pattern match
, ✔✔ fact - ✔✔related values
✔✔redundancy - ✔✔repetition of a fact
✔✔normal forms - ✔✔rules for designing tables with less redundancy
The six normal forms comprise a sequence, with each normal form allowing less
redundancy than the prior normal form.
✔✔What are the Normal Forms - ✔✔Normal forms are numbered, first normal form
through fifth normal form. An additional normal form, named Boyce-Codd normal form,
is considered an improved version of third normal form.
✔✔First normal form - ✔✔all non-key columns must depend on the primary key
✔✔What does dependence mean in an ERD? - ✔✔each instance of a dependent entity
always relates to an instance of another entity
Called: Existence dependence
✔✔What does dependence mean in a relational model? - ✔✔each value of a column
relates to at most one value of another column
Called: Functional dependence
✔✔second normal form - ✔✔all non-key columns must depend on the whole primary
key.
In other words, a non-key column cannot depend on part of a composite primary key.
✔✔Third normal form - ✔✔All non-key columns depend on the key, the whole key, and
nothing but the key.
✔✔In what situations is redundancy more acceptable? - ✔✔In a database used
primarily for reporting, changes are infrequent and redundancy is acceptable. In fact,
redundancy can be desirable in reporting databases, as processing is faster and
queries are simpler. For this reason, reporting databases may contain tables that, by
design, are not in third normal form.
✔✔Denormalization - ✔✔intentionally introducing redundancy by merging tables.
Denormalization eliminates join queries and therefore improves query performance.
