- A
OrderDate
Why wrong: Multiple orders can occur on the same date.
- B
OrderID
OrderID is unique per order.
- C
TotalAmount
Why wrong: TotalAmount can be same for different orders.
- D
CustomerID
Why wrong: CustomerID can repeat for multiple orders.
Question 790 of 1,000
DA0-001 Data Concepts and Environments Practice Question
This DA0-001 practice question tests your understanding of data concepts and environments. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A table named Orders has columns OrderID, CustomerID, OrderDate, and TotalAmount. Which column should be the primary key to uniquely identify each order?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"primary"Why it matters: Asks for the main purpose or function, not a secondary benefit. Eliminate answers that describe side-effects or partial functions.
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.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
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.
Clue confirmation
The clue word "primary" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
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.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates may 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.
Detailed technical explanation
How to think about this question
In relational database design, a primary key enforces entity integrity and is often implemented as a clustered index in systems like SQL Server, physically ordering the data. Using a surrogate key like OrderID (typically an auto-incrementing integer or GUID) avoids the complexities of natural keys, such as changes over time or non-uniqueness, and improves join performance. Real-world scenarios, such as e-commerce platforms, rely on OrderID to link orders to line items, payments, and shipments without ambiguity.
KKey Concepts to Remember
- Read the scenario before looking for a memorised answer.
- Find the constraint that changes the correct option.
- Eliminate answers that are true in general but not in this case.
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the DA0-001 exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
- →
Data Concepts and Environments — study guide chapter
Learn the concepts, then practise the questions
- →
Data Concepts and Environments practice questions
Targeted practice on this topic area only
- →
All DA0-001 questions
1,000 questions across all exam domains
- →
CompTIA Data+ DA0-001 study guide
Full concept coverage aligned to exam objectives
- →
DA0-001 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related DA0-001 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Data Concepts and Environments practice questions
Practise DA0-001 questions linked to Data Concepts and Environments.
Analysing Data practice questions
Practise DA0-001 questions linked to Analysing Data.
Visualising Data practice questions
Practise DA0-001 questions linked to Visualising Data.
Reporting Insights practice questions
Practise DA0-001 questions linked to Reporting Insights.
Mining Data practice questions
Practise DA0-001 questions linked to Mining Data.
Comparing and Contrasting Data Concepts practice questions
Practise DA0-001 questions linked to Comparing and Contrasting Data Concepts.
Mining and Acquiring Data practice questions
Practise DA0-001 questions linked to Mining and Acquiring Data.
Analyzing and Modeling Data practice questions
Practise DA0-001 questions linked to Analyzing and Modeling Data.
Visualizing Data practice questions
Practise DA0-001 questions linked to Visualizing Data.
Communicating Data Insights practice questions
Practise DA0-001 questions linked to Communicating Data Insights.
CompTIA A+ hardware practice questions
Practise DA0-001 questions linked to CompTIA A+ hardware.
CompTIA A+ mobile devices practice questions
Practise DA0-001 questions linked to CompTIA A+ mobile devices.
Practice this exam
Start a free DA0-001 practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this DA0-001 question test?
Data Concepts and Environments — This question tests Data Concepts and Environments — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: 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.
What should I do if I get this DA0-001 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "primary". Asks for the main purpose or function, not a secondary benefit. Eliminate answers that describe side-effects or partial functions.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Last reviewed: Jul 4, 2026
This DA0-001 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 DA0-001 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.