Given a table `orders` with a column `customer_id` that contains some NULL values, which query returns the number of orders that have a non-NULL customer_id?

SELECT COUNT(customer_id) FROM orders;

SELECT COUNT(DISTINCT customer_id) FROM orders;

SELECT SUM(customer_id) FROM orders;

A data analyst is analyzing customer satisfaction scores. The scores table has a column 'score' with values from 1 to 5, and some rows have NULL scores. The analyst needs to report the average score per region, but the business wants to understand the impact of NULLs. Which approach provides the most accurate representation of customer satisfaction?

Compute AVG(score) per region, ignoring NULLs.

Compute AVG(score) per region, treating NULLs as 0.

Compute both AVG(score) and COUNT(score) per region, and also report the percentage of NULLs.

Use MEDIAN(score) per region instead of AVG.

DatabricksCertified Data Analyst Associate

Domain 4Objective 5

Perform Aggregate Operations Such as Count, Approximate Count Distinct, Mean, and Summary Statistics. DATA-ANALYST-ASSOCIATE Practice Questions (Page 3)

Part of the Section 4: Executing queries using Databricks SQL and Databricks SQL Warehouses domain, which makes up ~22% of our current practice bank. Databricks does not publish an official question count, but from its 90-minute exam (~35–60 total, ~8–13 in this domain), expect 1–1 from this objective — we provide 16 practice questions to prepare you well beyond it. (estimate)

16questions here

4free pages

6concepts

Questions 11–15

11foundation · easy
Which SQL expression returns the number of unique non-NULL values in the `product_id` column?
Select an answer first
12foundation · easy
Given a table `orders` with a column `customer_id` that contains some NULL values, which query returns the number of orders that have a non-NULL customer_id?
Select an answer first
13foundation · easy
Which SQL function returns the number of rows in a table, including rows with NULL values?
Select an answer first
14foundation · easy
Which function is designed to return an approximate count of distinct values, trading a small amount of accuracy for faster performance on large datasets?
Select an answer first
15expert · hard
A data analyst is analyzing customer satisfaction scores. The scores table has a column 'score' with values from 1 to 5, and some rows have NULL scores. The analyst needs to report the average score per region, but the business wants to understand the impact of NULLs. Which approach provides the most accurate representation of customer satisfaction?
Select an answer first

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Perform Aggregate Operations Such as Count, Approximate Count Distinct, Mean, and Summary Statistics. DATA-ANALYST-ASSOCIATE Practice Questions (Page 3)

Questions 11–15

Which SQL expression returns the number of unique non-NULL values in the `product_id` column?

Given a table `orders` with a column `customer_id` that contains some NULL values, which query returns the number of orders that have a non-NULL customer_id?

Which SQL function returns the number of rows in a table, including rows with NULL values?

Which function is designed to return an approximate count of distinct values, trading a small amount of accuracy for faster performance on large datasets?

Keep studying — Section 4: Executing queries using Databricks SQL and Databricks SQL Warehouses