Subqueries
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What is Subqueries?
A subquery is a query nested inside another query, often referred to as the outer query. Subqueries are invaluable tools for retrieving information from multiple tables, performing complex calculations, or applying filter criteria based on the results of other queries. They can be found in various parts of SQL statements, such as SELECT, FROM, WHERE, and HAVING clauses.
Free resources to learn Subqueries
- Official docsPostgreSQL Subquery
- ArticlePostgreSQL Subquery
- ArticlePostgreSQL Subqueries
More in stage 9: Security
Subqueries: common questions
Can I learn Subqueries in Hindi?
This lesson is written in English. Once you sign in, open it in the interactive course and ask the AI tutor to explain Subqueries in Hindi or Hinglish. The tutor answers from this lesson’s own text, so it stays on the syllabus, and it runs on your own Google, OpenAI or Anthropic key.
Is this Subqueries tutorial for beginners?
It is lesson 58 of 170 in the free PostgreSQL roadmap, in stage 9, Security. If you are new to PostgreSQL, start from stage 1 and come back here in order; if you already know the earlier stages, this lesson stands on its own.