WGU Courses and Certificates Data-Management-Foundations Question # 6 Topic 1 Discussion

Aforeign keyis a column (or a set of columns) that establishes arelationship between two tablesby referencing theprimary key of another table.

Example Usage:

sql

CREATE TABLE Departments (

DeptID INT PRIMARY KEY,

DeptName VARCHAR(50)

);

CREATE TABLE Employees (

EmpID INT PRIMARY KEY,

Name VARCHAR(50),

DeptID INT,

FOREIGN KEY (DeptID) REFERENCES Departments(DeptID)

);

DeptID in Employees is a foreign key, referencing DeptID in Departments.

Ensuresreferential integrity→ DeptID in Employeesmust existin Departments.

Why Other Options Are Incorrect:

Option A (Super key) (Incorrect):Asuper keyis any set of columns that uniquely identifies a row, but itdoes not reference another table.

Option B (Simple key) (Incorrect):Asimple keyis asingle-column primary key, not a reference to another table.

Option C (Composite key) (Incorrect):Acomposite keyconsists ofmultiple columnsbut does not necessarily reference another table.

Thus, the correct answer isForeign key, as it establishes aconnection between two tables.