SQL code copied to buffer

Task 42:

What is "Aggregation" in SQL?

Mark all correct statements about aggregation in relational databases.

Aggregation possible only for numbers

Aggregation changes the level of detail (granularity) of a dataset, transforming atomic, row-level data into high-level metrics.

An aggregate is a summary statistic computed over a group of data - such as totals, averages, counts, minimums, maximums, or string concatenations.

Mark all correct answers and click the "Check!" button

Get hint

Support SQLtest.online

This project has only one funding source: your donations. The monthly maintenance cost is $100.

Last month I added a new MariaDB database with a preloaded University DB, 9 new questions, and refactored many questions and lessons.

With your support, I plan to continue this work: write new lessons and tasks, and improve existing lessons.

To keep the project running next month, we need to collect at least this amount by the end of this month. Anything above it goes to new lessons, exercises, and features.

Received: $16.10 Goal: $100.00

Progress: 16%

Learning SQL: Generate, Manipulate, and Retrieve Data by Alan Beaulieu

Learning SQL: Generate, Manipulate, and Retrieve Data by Alan Beaulieu

As data floods into your company, you need to put it to work right away―and SQL is the best tool for the job. With the latest edition of this introductory guide, author Alan Beaulieu helps developers get up to speed with SQL fundamentals for writing database applications, performing administrative tasks, and generating reports. You’ll find new chapters on SQL and big data, analytic functions, and working with very large databases.

Hi! Could we please enable some services and cookies to improve your experience and our website?

Privacy & Cookie Policy.