WGU Data-Management-Foundations Exam Dumps

In SQL, a primary key is explicitly defined using the PRIMARY KEY keyword when creating a table.

Example Usage:

sql

CREATE TABLE Products (

ProductID INT PRIMARY KEY,

Name VARCHAR(100),

Price DECIMAL(10,2)

);

Here, PRIMARY KEY is the SQL keyword that designates ProductID as the primary key.

Why Other Options Are Incorrect:

Option A (Formula in SQL) (Incorrect): SQL does not use formulas to define primary keys.

Option C (Bold typeface) (Incorrect): SQL syntax does not rely on text formatting.

Option D (Diamond symbol) (Incorrect): ER diagrams might use symbols, but SQL does not use diamonds to indicate keys.

Thus, the correct answer is SQL keyword, as primary keys are explicitly defined using PRIMARY KEY.

In database design, attributes of an entity become columns in a relational table.

Example Usage:

For an Employee entity, attributes might include:

CREATE TABLE Employees (

EmployeeID INT PRIMARY KEY,

Name VARCHAR(50),

Salary DECIMAL(10,2),

DepartmentID INT

);

Each attribute (e.g., Name, Salary) becomes a column in the table.

Why Other Options Are Incorrect:

Option A (Modality) (Incorrect): Describes optional vs. mandatory relationships, not table structure.

Option B (Uniqueness) (Incorrect): Ensures distinct values but is not a column property.

Option D (Non-null values) (Incorrect): Ensures that columns must contain data but does not define attributes.

Thus, the correct answer is Attribute, as attributes of entities become table columns.

A tangible entity is a real-world object that can be measured and stored in a database.

Example Usage:

In an inventory system, tangible entities include:

Products, Orders, Customers

Why Other Options Are Incorrect:

Option A (Logical entity) (Incorrect): Exists logically but may not have a physical presence (e.g., views, categories).

Option C (Virtual entity) (Incorrect): Exists only in queries or reports, not stored as real data.

Option D (Conceptual entity) (Incorrect): Abstract idea used in design modeling, not a stored entity.

Thus, the correct answer is Tangible entity, as it represents measurable, real-world objects.

The ON keyword specifies the field used by an index when creating it in SQL.

Example Usage:

sql

CREATE INDEX idx_employee_name

ON Employees(Name);

Here, an index idx_employee_name is created on the Name column.

This improves query performance when filtering by Name.

Why Other Options Are Incorrect:

Option B (IN) (Incorrect): Used in queries to match values in a set, not for indexing.

Option C (UNIQUE) (Incorrect): Ensures a column has unique values but does not define an index field.

Option D (CHECK) (Incorrect): Used for validating column values, not for indexing.

Thus, the correct answer is ON, as it defines the column on which an index is created.

The logical design phase in database development focuses on structuring data efficiently to eliminate redundancy and ensure integrity. The final step in logical design is to apply normalization (normal forms) to optimize the database schema.

Steps in Logical Database Design:

Discover entities Identify real-world objects (e.g., Customers, Orders).

Determine cardinality Define relationships between entities (one-to-one, one-to-many).

Analyze data requirements Determine the attributes each entity needs.

Apply normal forms Eliminate redundancy and improve data consistency.

Example Usage:

After identifying entities like Students and Courses, applying 3rd Normal Form (3NF) ensures that data is organized without redundancy.

Why Other Options Are Incorrect:

Option A (Analyze data requirements) (Incorrect): Done earlier to define attributes.

Option C (Determine cardinality) (Incorrect): Done before normalization to establish relationships.

Option D (Discover entities) (Incorrect): Done at the beginning of database design.

Thus, the correct answer is Apply a normal form, as normalization is the last step in logical design.