Correlated subquery in sql

Overview

Subqueries are queries that are nested inside another SQL query.

Types of subqueries in sql w3schools

They help us target specific rows to perform various operations in SQL. They are used to SELECT, UPDATE, INSERT and DELETE records in SQL. There are different types of SQL subquery, like Single-row subquery, multiple row subquery, multiple column subquery, correlated subquery, and nested subquery.

Each type performs different roles, and their result is used depending on the user's requirement.

Introduction

Subqueries are queries that are nested within another SQL query. A subquery can contain more than one query inside it, one after another.

They allow us to select specific rows that satisfy certain conditions at the run time. They are also known as the inner query or inner select, and the query that contains them is known as the outer query or outer select.

• Subqueries are nested inside statements like SELECT, INSERT, UPDATE, DELETE, or any other subquery.
• Subqueries are present in the WHERE clause, FROM clause, or HAVING clause of the PARENT SQL query.
• They are used w
  how many types of subqueries in sql server
  how many types of subqueries in sql