WGU D427 DATABASE MANAGEMENT
COMPREHENSIVE REVIEW 2026
QUESTIONS WITH ANSWERS GRADED A+
◉What is a table row called? Answer: A tuple or record.
◉What is a table column called? Answer: An attribute.
◉What is a primary key? Answer: A column (or columns) that
uniquely identifies each row in a table
Rules:
1. Cannot contain NULL
2. Must be unique
◉What is a foreign key? Answer: A column that references the
primary key of another table to create a relationship.
◉What is the basic SELECT syntax? Answer: SELECT column1,
column2
FROM TableName;
,◉How do you select all columns? Answer: Using the asterisk (*) key
with the SELECT clause.
SELECT *
FROM TableName;
◉How do you filter the SELECT clause to return only specific
criteria? Answer: using the WHERE clause, which comes after the
FROM Table clause.
SELECT column
FROM TableName
WHERE condition;
exp:
SELECT CourseName
FROM Course
WHERE Capacity > 100;
◉What are the SQL Comparison operators? Answer: Operator
Meaning
= Equals
, <> or != Not Equal
> Greater Than
< Less Than
>= Greater or Equal
<= Less or Equal
◉What are the Logical Operators in SQL? Answer: AND both
conditions are true
OR One condition is true
NOT Reverses the condition
(T -> F), (F -> T)
◉How do you check for NULL Value? Answer: WHERE column IS
NULL.
◉How do you check for Values which are NOT NULL? Answer:
WHERE column IS NOT NULL.
◉What is the ORDER BY syntax? Answer: SELECT column
FROM TableName
ORDER BY column;
COMPREHENSIVE REVIEW 2026
QUESTIONS WITH ANSWERS GRADED A+
◉What is a table row called? Answer: A tuple or record.
◉What is a table column called? Answer: An attribute.
◉What is a primary key? Answer: A column (or columns) that
uniquely identifies each row in a table
Rules:
1. Cannot contain NULL
2. Must be unique
◉What is a foreign key? Answer: A column that references the
primary key of another table to create a relationship.
◉What is the basic SELECT syntax? Answer: SELECT column1,
column2
FROM TableName;
,◉How do you select all columns? Answer: Using the asterisk (*) key
with the SELECT clause.
SELECT *
FROM TableName;
◉How do you filter the SELECT clause to return only specific
criteria? Answer: using the WHERE clause, which comes after the
FROM Table clause.
SELECT column
FROM TableName
WHERE condition;
exp:
SELECT CourseName
FROM Course
WHERE Capacity > 100;
◉What are the SQL Comparison operators? Answer: Operator
Meaning
= Equals
, <> or != Not Equal
> Greater Than
< Less Than
>= Greater or Equal
<= Less or Equal
◉What are the Logical Operators in SQL? Answer: AND both
conditions are true
OR One condition is true
NOT Reverses the condition
(T -> F), (F -> T)
◉How do you check for NULL Value? Answer: WHERE column IS
NULL.
◉How do you check for Values which are NOT NULL? Answer:
WHERE column IS NOT NULL.
◉What is the ORDER BY syntax? Answer: SELECT column
FROM TableName
ORDER BY column;