DS0-001 Database Structures And SQL Practice Question
A developer needs to ensure that a 'Customer_ID' field in a 'Orders' table always references a valid ID in the 'Customers' table. Which constraint should be applied?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
FOREIGN KEY
A foreign key constraint ensures referential integrity between two tables by requiring that the value in the child table exists in the parent table.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
PRIMARY KEY
Why it's wrong here
PRIMARY KEY uniquely identifies a record in a table.
- ✗
UNIQUE
Why it's wrong here
UNIQUE ensures all values in a column are distinct.
- ✗
CHECK
Why it's wrong here
CHECK validates data against a specific condition.
- ✓
FOREIGN KEY
Why this is correct
FOREIGN KEY enforces referential integrity between tables.
About these practice questions
Courseiva writes every DS0-001 question from scratch — 216 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed August 2026 · checked against the official CompTIA exam blueprint
This DS0-001 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the DS0-001 exam.