DA0-002 Data Concepts and Environments Practice Question
A table named Orders has columns OrderID, CustomerID, OrderDate, and TotalAmount. Which column should be the primary key to uniquely identify each order?
⚠ Common exam trap
Test-takers frequently confuse a column that is frequently used for filtering or grouping (like CustomerID or OrderDate) with one that guarantees uniqueness, overlooking the fundamental primary key requirement of uniqueness and non-nullability.
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
✓
OrderID
The OrderID column is the correct choice for the primary key because it contains unique values for each order, ensuring that each row can be uniquely identified. A primary key must be unique, non-null, and stable; OrderID satisfies all these requirements, whereas the other columns do not guarantee uniqueness or are subject to change.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
OrderDate
Why it's wrong here
Multiple orders can occur on the same date.
- ✓
OrderID
Why this is correct
OrderID is unique per order.
- ✗
TotalAmount
Why it's wrong here
TotalAmount can be same for different orders.
- ✗
CustomerID
Why it's wrong here
CustomerID can repeat for multiple orders.
Go deeper
Related to this question
About these practice questions
This DA0-002 question is part of Courseiva's 986-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DA0-002 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 DA0-002 exam.