WGU Data-Management-Foundations Exam With Confidence Using Practice Dumps

Anintangible entityis an entity that does not have a physical presence but still holds meaning in a database. These entities representconcepts, relationships, or abstract datathat exist in a logical sense.

Example Usage in Databases:

Customer Loyalty Status (Gold, Silver, Bronze)

Theloyalty levelis anintangible entitysince it is derived from other data (purchase history).

Online User Sessions

Asession IDexistslogically in the systembut does not have a tangible presence like a product or employee.

Why Other Options Are Incorrect:

Option A (Concrete entity) (Incorrect):No such formal term in database design.

Option B (Tangible entity) (Incorrect):Represents somethingphysical, like anemployeeorproduct.

Option D (Physical entity) (Incorrect):Refers todata stored on disk, like database tables or indexes.

Thus, the correct answer isIntangible entity, as it only exists in a logical sense within the database.

Anaggregate functionperforms acalculation over multiple rowsand returns asingle value. Examples includeSUM(), AVG(), MAX(), MIN(), and COUNT()in SQL.

Option A (Correct):Aggregate functions compute values over aset of rows, like summingtotal sales or averaging grades.

Option B (Incorrect):Selecting rows that appear in one table but not another is done usingset operations (EXCEPT or MINUS in SQL).

Option C (Incorrect):Eliminating columns is done using thePROJECToperation orSELECT with specific columns.

Option D (Incorrect):Combining rows from two tables refers to aJOIN operation, not aggregation.

When performing aJOIN operationin MySQL, the ON clause specifies thejoining condition, defining which columns from both tables should be matched.

Example:

sql

SELECT Employees.Name, Departments.DepartmentName

FROM Employees

JOIN Departments ON Employees.DepartmentID = Departments.ID;

Option A (Incorrect):AS is used foraliasing tables and columns, not for specifying join conditions.

Option B (Incorrect):JOIN defines the type of join (INNER JOIN, LEFT JOIN, etc.), butdoes not specify the columns.

Option C (Correct):The ON clause is used tospecify the join conditionbetween two tables.

Option D (Incorrect):AND is used in filtering conditions, not for joining tables.