# 1z0-071 — Question 602

**Type:** multiple_response
**Topics:** topic_1

## Question

Examine the description of the PROMOTIONS table:
//IMG//

You want to display the unique promotion costs in each promotion category.
Which two queries can be used? (Choose two.)

## Correct Answer

_See scenario._

## Explanation

-- Distinct keyword is used to select the unique values of the column/combination of columns mentioned after the DISTINCT clause.
 
 Thus Option E is incorrect , as this does not use DISTINCT clause and might include duplicates.
 
 -- Distinct should be used once in a SELECT statement and should be used IMMEDIATELY after the SELECT clause. NOT to be used before every column.
 
 Thus Options D and B are incorrect, as the positioning of the DISTINCT clause is incorrect.
 
 -- Option A and C are correct.
 
 Option A: Even though there is a string ' has ' in everyrow returned , the combination of promo_category || ' has ' || promo_cost will still be distinct.
 Option C: correct use case. ORDER BY clause does not affect the uniqueness in the returned result set.

**Reference:** examtopics_top_comment

---
Source: https://hiexam.net/q/oracle/1z0-071/602  
Practice (tracked): https://hiexam.net/study/1z0-071/practice