How do I use GROUP BY in SQL?

How do I use GROUP BY in SQL?

The GROUP BY statement is used to arrange identical data into groups. It often works with aggregate functions like COUNT, SUM, AVG, etc.

Can you give me an example of using GROUP BY with COUNT?

Sure! If you have a table called 'employees' and you want to count how many employees are in each department, you can use:

SELECT department, COUNT(*) as employee_count
FROM employees
GROUP BY department;

What if I want to filter the results after grouping?

You can use the HAVING clause to filter results after grouping. For example:

SELECT department, COUNT(*) as employee_count
FROM employees
GROUP BY department
HAVING COUNT(*) > 5;
``` This will show only departments with more than 5 employees.

Is GROUP BY case-sensitive?

It depends on the collation settings of your database. By default, many databases are case-insensitive, but you can specify case-sensitive collations if needed.