SQL Execution Order

SQL Execution Order is a SQL statement in the SELECT Queries category. The logical order SQL processes a query. Understanding this is key to writing correct SQL. The syntax is -- FROM -> WHERE -> GROUP BY -> HAVING -> WINDOW -> SELECT -> DISTINCT -> UNION -> ORDER BY -> LIMIT/OFFSET.. It returns conceptual query processing order. A typical example: SELECT department, AVG(salary) AS avg_sal FROM employees WHERE hire_date > '2020-01-01' GROUP BY department HAVING AVG(salary) > 50000 ORDER BY avg_sal DESC LIMIT 5; -- Execution order: -- 1. FROM employees (get the table) -- 2. WHERE hire_date > '2020-01-01' (filter rows) -- 3. GROUP BY department (group) -- 4. HAVING avg_sal > 50000 (filter groups) -- 5. SELECT department, AVG(salary) (compute columns) -- 6. ORDER BY avg_sal DESC (sort)… A close relative is SELECT, which retrieves data from a table. The most fundamental SQL statement. A close relative is SELECT *, which selects all columns from a table.