Aggregate Functions

Jill Thornhill

The SQL MIN() Function

SQL has a variety of powerful aggregate tools, including the SQL MIN() function. This article is a quick reference guide to extracting and using minimum values in your queries. In today’s cutthroat business environment, it’s vital to be able to analyze your organization’s data effectively to make informed decisions. SQL’s aggregate functions let you carry out all kinds of statistical analysis on your data. This article is a reference guide to the SQL MIN() function, which extracts the smallest item from a column of data.

Tihomir Babic

GROUP BY and Aggregate Functions: A Complete Overview

SQL’s GROUP BY and aggregate functions are essential in data aggregation – and for analyzing data and creating reports. Let’s explore them together!   In SQL, GROUP BY and aggregate functions are one of the language’s most popular features. Data aggregation is critical for data analysis and reporting; to make sense of all the data in a dataset, it often needs to be aggregated. But what is data aggregation? Put simply, it’s when you group data based on common values and perform a calculation for each data group.

Agnieszka Kozubek-Krycuń

SQL MAX Function

Learn about the SQL MAX function, which is used to find the highest value in your dataset. This article explains how to use the syntax of MAX function and shows typical usage examples. The SQL MAX function is an aggregate function that returns the maximum value in a column. MAX function, together with its counterpart MIN function, is useful for summarizing data in data analysis. It can help you to compute the range of values in a dataset.

Jill Thornhill

SQL Aggregate Functions Cheat Sheet

A quick reference guide to using SQL aggregate functions. This SQL Aggregate Functions Cheat Sheet is designed to be your companion whenever you’re using SQL for data analysis. Aggregating data is essential for any meaningful data analysis. SQL provides a set of functions that allow you to include totals, averages, and counts in your reports and to extract the minimum and maximum value of any column of data.

Maria Durkin

SQL Aggregate Functions: A Comprehensive Guide for Beginners

Are you curious about SQL aggregate functions and how they apply to real-world scenarios? In this article, we'll explore SQL aggregate functions, showcase real-world examples, and offer valuable insights on how to master them. Data aggregation is the process of taking several rows of data and condensing them into a single result or summary. When dealing with large datasets, this is invaluable because it allows you to extract relevant insights without having to scrutinize each individual data point.

Radu Gheorghiu

How to Use COUNT() with GROUP BY: 5 Practical Examples

Using the COUNT() function with GROUP BY is one of the most common SQL constructs in aggregate queries. Read this article to find out how to use COUNT() with GROUP BY correctly using 5 examples. In this article, we will explain the importance of using COUNT with GROUP BY. We’ll talk about why it is essential in SQL and how it enables data analysis and summarization based on specific criteria.

Gustavo du Mortier

How to Use SUM() with GROUP BY: A Guide with 8 Examples

Explore some real-world examples of using SUM() and GROUP BY in SQL, from the most basic to the most sophisticated. SUM() is a SQL aggregate function that computes the sum of the given values. GROUP BY is a SQL clause that partitions rows into groups and computes a stated aggregate function for each group. Using these two functions together, you can compute total sums for a group of rows. In this article, we’ll see 8 different examples of how you can combine SUM() and GROUP BY to create many different reports.

Tihomir Babic

The SQL COUNT() Function: A Detailed Guide

Updated on: April 22, 2024 This guide will give you a detailed explanation (with examples) of all the typical uses of the COUNT() function. Exercises included! The COUNT() function in SQL is one of the most commonly used aggregate functions. Aggregate functions in SQL are used to calculate statistics for a group of rows: counting the number of rows in each group, computing the sum of values in a group, finding the minimum or maximum value in a group, and so on.

Tihomir Babic

How to Use Aggregate Functions in WHERE Clause

Filtering data according to the result of an aggregate function is a common data analysis task. So how do you use aggregates in the  WHERE clause? We’ll dedicate this whole article to answering that question.   Combining aggregate functions and filtering based on their results is often used in data analysis – e.g. showing branches with total sales above X,  countries where the number of posts is lower than Y, students with an average score below Z, and so on.

Tihomir Babic

How to Combine Two Aggregate Functions in SQL

Having trouble using two aggregate functions in one query? This article will show you how to do it the right way – actually, the two right ways. In data analysis and reporting, we often need to count the number of records or sum them up and then calculate the average of this count or sum. Translated to SQL logic, this is the aggregation of aggregated data, or multi-level aggregation. For aggregation purposes, there are the SQL aggregate functions.

Tihomir Babic

How to Include Zero in a COUNT() Aggregate

Explaining how to include zero (0) counts in your SQL query result. Here’s the problem: you want to count something that doesn’t exist, and you want to show your result as zero. How do you do that in SQL? Using the COUNT() aggregate function is a reasonable first step. It will count all the data it finds and return the number of occurrences. But what if there are no occurrences of certain data?

Martyna Sławińska

What Are Aggregate Functions in SQL, and How Do I Use Them?

Data is your source of knowledge. And thanks to SQL aggregate functions, you can extract the precise knowledge you need from your data efficiently. Read along to find out more. The core SQL aggregate functions are the following: COUNT(column_name | *) returns the number of rows in a table. SUM(column_name) returns the sum of the values of a numeric column. AVG(column_name) returns the average value of a numeric column.

Himanshu Kathuria

The SQL Count Function Explained With 7 Examples

One of the most useful aggregate functions in SQL is the COUNT() function. If you are new to SQL and want to learn about the various ways to use the COUNT() function with some practical examples, this article is for you. The COUNT() function is one of the most useful aggregate functions in SQL. Counting the total number of orders by a customer in the last few days, the number of unique visitors who bought a museum ticket, or the number of employees in a department, can all be done using the COUNT() function.

Dorota Wdzięczna

SQL MIN and MAX Functions Explained in 6 Examples

What are the SQL MIN() and MAX() functions? When should you use them as aggregate functions, and when should you use them with window functions? We explain using practical examples. It’s difficult to imagine SQL without the MIN() and MAX() aggregate functions. They are very useful among many data professionals because they allow us to resolve a lot of business problems. In this article, I will explain what each function does and discuss several use cases.

Himanshu Kathuria

The SQL AVG() Function Explained With Examples

We explain the SQL AVG() function with practical examples, covering how and where you can and cannot use it. The average is probably one of the most widely used metrics to describe some characteristics of a group. It is so versatile and useful that it can describe something about almost anything. If you like sports, you see things like average runs per game in baseball, average assists per game or per season in basketball, and so on.

Dorota Wdzięczna

SQL SUM() Function Explained with 5 Practical Examples

Aggregate functions are an important part of SQL knowledge – and there’s no better place to start learning them than with the SUM() function. In this article, you can expand or refresh your SQL with 5 practical examples of SUM(). SQL allows us to do more than select values or expressions from tables. Most operations on relational databases use aggregate functions like SUM() to do computations on data.

Tihomir Babic

How to Use CASE WHEN With SUM() in SQL

This article will teach you what a CASE WHEN expression is in SQL and how to use it with a SUM() function and a GROUP BY statement. The examples are included to bolster your understanding. The best way to learn about CASE WHEN and how to use it with SUM() is our hands-on course Creating Basic SQL Reports. It contains over 90 interactive exercises that will teach you different techniques how to create complex reports in SQL.

Kateryna Koidan

Aggregate Functions vs Window Functions: A Comparison

If you aren’t familiar with SQL’s window functions, you may wonder how they differ from aggregate functions. When should you use window functions? In this article, we’ll review window functions and aggregate functions, examine their similarities and differences, and see which one to choose depending on what you need to do. After you’ve tackled basic SQL, you’ll probably want to get into some of its more advanced functions. That’s great; these functions make reporting and analysis easier.

Tihomir Babic

What is the Difference Between COUNT(*), COUNT(1), COUNT(column), and COUNT(DISTINCT)?

Have you noticed there are different variations of the SQL COUNT() function? This article explains the various arguments and their uses. As a SQL user, you’re probably quite familiar with the COUNT() function. Even though it’s relatively simple, it can be used in several different ways. Each way has a very different use. I imagine you’ve seen code that contains the function COUNT(*) or COUNT(1). You’ve probably also seen some other uses of the COUNT() function, such as COUNT(column name) and COUNT(DISTINCT column name), even if you haven’t used them.

Ignacio L. Bisso

SQL Date and Interval Arithmetic: Employee Lateness

Computing Tardiness: Date, Time, and Interval SQL Arithmetic In this article, we’re going to discuss some interesting operations we can perform with date-related data types in SQL. The SQL standard, which most relational databases comply with these days, specifies the date-related data types that must be present in relational databases. The most important of such data types are date, time, timestamp, and interval. Here’s a brief rundown of the differences between these data types:

Aldo Zelen

Common SQL Window Functions: Positional Functions

Positional SQL window functions deal with data's location in the set. In this post, we explain LEAD, LAG, and other positional functions. SQL window functions allow us to aggregate data while still using individual row values. We've already dealt with ranking functions and the use of partitions. In this post, we'll examine positional window functions, which are extremely helpful in reporting and summarizing data. Specifically, we'll look at LAG, LEAD, FIRST_VALUE and LAST_VALUE.

Dejan Sarka

Statistics in SQL: Measuring Spread of Distribution

Besides knowing the centers of a distribution in your data, you need to know how varied the observations are. In this article, we’ll explain how to find the spread of a distribution in SQL. Are you dealing with a very uniform or a very spread population? To really understand what the numbers are saying, you must know the answer to this question. In the second part of this series, we discussed how to calculate centers of distribution.

Francisco Claria

An Introduction to Using SQL Aggregate Functions with JOINs

Previously, we've discussed the use of SQL aggregate functions with the GROUP BY statement. Regular readers of the our blog will also remember our recent tutorial about JOINs. If you're a bit rusty on either subject, I encourage you to review them before continuing this article. That's because we will dig further into aggregate functions by pairing them with JOINs. This duo unleashes the full possibilities of SQL aggregate functions and allows us to perform computations on multiple tables in a single query.

Maria Alcaraz

NULL Values and the GROUP BY Clause

We've already covered how to use the GROUP BY clause and some aggregation functions like SUM(), AVG(), MAX(), MIN(), COUNT(). In this article, we will explain how the GROUP BY clause works when NULL values are involved. We will also explain about using NULLs with the ORDER BY clause. The best way to master GROUP BY and NULL in SQL is through practice. I recommend the SQL Practice track at LearnSQL.