How does the order of execution of SQL queries with JOIN, WHERE, and GROUP BY occur?

The typical order of executing an SQL query with JOIN, WHERE, and GROUP BY is:

1. FROM and JOIN — first, tables are selected and joined (JOIN), forming the initial dataset.
2. WHERE — filtering rows from the JOIN result based on specified conditions.
3. GROUP BY — grouping the filtered data by specified columns.
4. HAVING (if present) — filtering grouped data.
5. SELECT — selecting columns and calculating aggregate functions.
6. ORDER BY — sorting the result.
7. LIMIT — limiting the number of returned rows.

For example, the query:

SELECT department, COUNT(*)
FROM employees
JOIN departments ON employees.dept_id = departments.id
WHERE salary > 50000
GROUP BY department

First, the employees and departments tables are joined, then employees with a salary above 50,000 are filtered, after which the data is grouped by departments and the number of employees in each is counted.