Answer
A subquery is a query inside another query used for filtering, comparisons, or dynamic data selection.
Quick Answer
A subquery is a SELECT statement nested inside another SQL statement. Can appear in WHERE (filter with subquery result), FROM (inline view/derived table), SELECT (scalar subquery). Correlated subquery references the outer query's columns and executes once per outer row (can be slow). Non-correlated subquery executes once, result reused. Often replaceable with JOINs for better performance.
S
SugharaIQ Editorial Team
Verified Answer
This answer has been peer-reviewed by industry experts holding senior engineering roles to ensure technical accuracy and relevance for modern interview standards.
Want to bookmark, take notes, or join discussions?
Sign in to access all features and personalize your learning experience.
Source: SugharaIQ