If you've been writing SQL for a while, you've hit this wall your query works, but it's a mess of nested parentheses and you can barely read it yourself. That's the moment subqueries and CTEs become your best friends. Both tools let you break complex logic into manageable steps. Subqueries A subquery is a query inside another query. The inner query runs first, and its result is used by the outer query. The Classic Use Case Say you want to find all employees earning above the company average: SELECT name , salary FROM employees WHERE salary > ( SELECT AVG ( salary ) FROM employees ); Enter fullscreen mode Exit fullscreen mode The inner query calculates the average first let's say 58,000 then the outer query filters for everyone above that. Simple and effective.…