Use SQL HAVING to filter summary results from a GROUP BY. It
When you group and summarize SQL results, you use the GROUP BY Clause to output a row across specified column values. It is typically used in conjunction with aggregate functions such as SUM or Count to summarize values. In SQL, groups are unique combinations of fields. Rather than returning every row in a table, when values are grouped, only the unique combinations are returned.
If you want to start to learn about grouping data, I would recommend first reading this article: How to Use GROUP BY to Summarize Query Results
Once you understand how to group and summarize data, I would recommend reading the following:
- What is the Difference between ORDER and GROUP BY?
- What is the difference between WHERE and HAVING clauses?
These article will help you understand the subtle, yet important differences between these commands.
All the examples for this lesson are based on Microsoft SQL Server Management Studio and the sample databases AdventureWorks and WideWorldImporters. You can get started using these free tools using my guide Getting Started Using SQL Server
Use the SQL GROUP BY Clause is to consolidate like values into a single row. The group is a set of columns. The group
The SQL SUM function returns the total value within a table or group. In its simplest use, SUM() totals a column for all results and returns a
In this article learn when to use WHERE and HAVING. Both perform similar functions, but for different purposes! All the examples for
The SQL COUNT function is an aggregate function used to count rows. Use it alone within a SELECT statement to return a count of all rows within
Use the Approximate Count Distinct function, APPROX_COUNT_DISTINCT, to return an estimate distinct count of values withing rows. It is best suited for
The SQL MIN function returns the smallest value within a table or group. Throughout this section we’ll use the HumanResource.Employee table for our examples: Using the
The SQL MAX function returns the largest value within a table or group. In this section, we’ll use the HumanResource.Employee table for our examples: Using the data above, MAX calculates
The SQL AVG function returns the average value within a table or group. In this section, we’ll use the HumanResource.Employee table for our examples: Using sample data above, AVG calculates
In this episode of SQL Minute I want to share with you how to create a pivot or cross tab chart. I’ll
The running total in SQL can be calculated in several ways. This article will cover two methods: the Joins and the Window functions.
In this puzzle, we’re going to learn how to create a dynamic pivot table using SQL Server. A dynamic pivot table is
Both the GROUP and ORDER BY clauses are used in organizing data. Find out which of the two is used to sort
