Millises järjekorras täidetakse SQL-i operaatorid päringus?

Order of execution of SQL operators in a query differs from the order in which they are written and is usually as follows:

1. FROM — tables are selected and joins are performed.
2. WHERE — rows are filtered according to conditions.
3. GROUP BY — rows are grouped by specified columns.
4. HAVING — grouped data is filtered.
5. SELECT — columns are selected and expressions are calculated.
6. ORDER BY — the result is sorted.
7. LIMIT / OFFSET — the number of returned rows is limited.

This order is important for understanding how the query is processed exactly and how to optimize its execution.