How to Work with Subqueries in SQL
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EDITOR BRIEF
A subquery is a query nested inside another SQL query. The excerpt explains that the inner query can supply a derived value or table, or help filter rows in the outer query, and it introduces basic execution order plus non-correlated and correlated subqueries. It also notes that subqueries build on SQL basics like SELECT, FROM, WHERE, JOINs, CASE, and query order.
INSIGHTS
Subqueries are a key step beyond basic SELECT and WHERE queries. Try rewriting a simple filter query using an IN subquery, then compare it with a JOIN to see how each approach works.
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