When a SQL query executes on SQL Server, it follows a specific sequence known as the Logical Query Processing Order. While we write queries starting with SELECT, SQL Server processes them in a very different order to ensure data is filtered and grouped correctly before being returned. Understanding this flow is essential for writing efficient code and troubleshooting unexpected results. Let’s break down the logical order of a SELECT statement.
1. FROM
2. ON
3. OUTER
4. WHERE
5 GROUP BY
6 CUBE or ROLLUP
7 HAVING
8 SELECT
9 DISTINCT
10 ORDER BY
11 TOP
