WGU D426/D427 Comprehensive Database Applications & SQL
Mastery Study Guide: Subqueries, SQL Aliases, Materialized Views,
WITH CHECK OPTION, Entity Relationship Modeling, ER Diagrams,
Entities, Relationships, Attributes, Entity Types, Relationship Types,
Cardinality, Subtypes, Supertypes, IsA Relationships, Crow’s Foot
Notation, Database Keys, Primary Keys, Artificial Keys, Candidate
Keys, Functional Dependencies, Database Redundancy,
Normalization Principles, Third Normal Form (3NF), Boyce-Codd
Normal Form (BCNF), Data Modeling, Relational Database Design,
Database Integrity, SQL Concepts, Advanced Database Structures,
Objective Assessment Preparation, Practice Questions, Detailed
Explanations Reviewed 2026
What is a subquery
A query within another SQL query.
What is an alias in SQL
A temporary name assigned to a column or table, created with the AS keyword.
What is a materialized view
A view for which data is stored at all times and must be refreshed when the base table
changes.
What does the WITH CHECK OPTION clause do
Ensures that inserts and updates in a view satisfy the view's WHERE clause.
,What is an entity in entity-relationship modeling
A person, place, product, concept, or activity.
What is a relationship in entity-relationship modeling
A statement about two entities.
What is an attribute in entity-relationship modeling
A descriptive property of an entity.
What is a reflexive relationship
A relationship that relates an entity to itself.
What is an entity-relationship diagram (ER diagram)
A schematic picture of entities, relationships, and attributes, where entities are drawn as
rectangles.
What is an entity type
A set of things, such as all employees in a company.
, What is a relationship type
A set of related things, such as employee-manages-department pairs.
What is an attribute type
A set of values, such as all employee salaries.
What is an entity instance
An individual thing, such as the employee Sam Snead.
What is a relationship instance
A specific statement about entity instances, such as "Maria Rodriguez manages Sales."
What is an attribute instance
An individual value, such as a salary of $35,000.
What is cardinality in entity-relationship modeling
The maxima and minima of relationships and attributes.
What is a subtype entity
Mastery Study Guide: Subqueries, SQL Aliases, Materialized Views,
WITH CHECK OPTION, Entity Relationship Modeling, ER Diagrams,
Entities, Relationships, Attributes, Entity Types, Relationship Types,
Cardinality, Subtypes, Supertypes, IsA Relationships, Crow’s Foot
Notation, Database Keys, Primary Keys, Artificial Keys, Candidate
Keys, Functional Dependencies, Database Redundancy,
Normalization Principles, Third Normal Form (3NF), Boyce-Codd
Normal Form (BCNF), Data Modeling, Relational Database Design,
Database Integrity, SQL Concepts, Advanced Database Structures,
Objective Assessment Preparation, Practice Questions, Detailed
Explanations Reviewed 2026
What is a subquery
A query within another SQL query.
What is an alias in SQL
A temporary name assigned to a column or table, created with the AS keyword.
What is a materialized view
A view for which data is stored at all times and must be refreshed when the base table
changes.
What does the WITH CHECK OPTION clause do
Ensures that inserts and updates in a view satisfy the view's WHERE clause.
,What is an entity in entity-relationship modeling
A person, place, product, concept, or activity.
What is a relationship in entity-relationship modeling
A statement about two entities.
What is an attribute in entity-relationship modeling
A descriptive property of an entity.
What is a reflexive relationship
A relationship that relates an entity to itself.
What is an entity-relationship diagram (ER diagram)
A schematic picture of entities, relationships, and attributes, where entities are drawn as
rectangles.
What is an entity type
A set of things, such as all employees in a company.
, What is a relationship type
A set of related things, such as employee-manages-department pairs.
What is an attribute type
A set of values, such as all employee salaries.
What is an entity instance
An individual thing, such as the employee Sam Snead.
What is a relationship instance
A specific statement about entity instances, such as "Maria Rodriguez manages Sales."
What is an attribute instance
An individual value, such as a salary of $35,000.
What is cardinality in entity-relationship modeling
The maxima and minima of relationships and attributes.
What is a subtype entity
