DA0-002 Data Acquisition and Preparation Practice Question
A data analyst needs to retrieve only unique job titles from the 'employees' table. Which SQL keyword should be used in the SELECT clause?
⚠ Common exam trap
The trap is confusing the UNIQUE constraint (a DDL keyword) with DISTINCT (a DML query keyword), leading candidates to pick UNIQUE for deduplication in a SELECT statement.
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
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DISTINCT
The DISTINCT keyword in the SELECT clause removes duplicate rows from the result set, so 'SELECT DISTINCT job_title FROM employees' returns each unique job title only once. It is the standard SQL keyword defined in the SQL standard for deduplication of result rows. DISTINCT applies to the entire selected column list, not just one column.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
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TOP
Why it's wrong here
TOP limits the number of rows returned in SQL Server, so it truncates the result set without removing duplicate job titles. It cannot deduplicate values. DISTINCT is the keyword that returns unique job titles; TOP would be correct when only the first N rows are required.
- ✓
DISTINCT
Why this is correct
DISTINCT in the SELECT clause removes duplicate rows from the result set, so repeated job titles collapse to a single occurrence. This satisfies the requirement to retrieve only unique job titles from the employees table.
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UNIQUE
Why it's wrong here
UNIQUE is a table or index constraint enforcing distinct values on a column, not a SELECT clause keyword. Placed in SELECT it produces a syntax error rather than deduplicating output rows. DISTINCT is the keyword that returns unique job titles; UNIQUE belongs in DDL when defining constraints.
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FILTER
Why it's wrong here
FILTER is a clause applied to aggregate functions to restrict which rows feed the aggregation, not a SELECT keyword for deduplication. It cannot remove duplicate job titles. DISTINCT is the keyword that returns unique values; FILTER would be correct when limiting rows counted by an aggregate such as COUNT.
About these practice questions
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Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official CompTIA exam blueprint
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.