Apr 14, 2025 · In SQL, a subquery can be defined as a query embedded within another query. It is often used in the WHERE , HAVING , or FROM clauses of a statement. Subqueries are commonly used with SELECT , UPDATE , INSERT, and DELETE statements to achieve complex filtering and data manipulation .

Aug 3, 2021 · This article illustrated how to write a subquery in SQL within the SELECT, FROM, and WHERE clauses. Even if this ability is interesting in structured Query Language (SQL), developers should use it carefully since it may affect the query performance.

Summary: In this tutorial, you’ll learn how to use SQL subqueries to form flexible queries for retrieving data from the database. A subquery is an SQL query nested inside another query. The query that contains a subquery is known as an outer query. To write a subquery, you need to have a deep understanding of the SELECT statement: select_list.

Nov 18, 2021 · Here are 5 SQL subquery examples demonstrating how to use scalar, multirow, and correlated subqueries in the WHERE, FROM, JOIN, and SELECT clauses.

Feb 13, 2025 · What is subquery in SQL? A subquery is a SQL query nested inside a larger query. The subquery can be nested inside a SELECT, INSERT, UPDATE, or DELETE statement or inside another subquery. A subquery is usually added within the WHERE Clause of another SQL SELECT statement. You can use the comparison operators, such as >, <, or =.

In a subquery, the outer query's result depends on the result set of the inner subquery. That's why subqueries are also called nested queries. Here is how this code works: Suppose we want the details of customers who have placed an order. We can achieve that by using a subquery. FROM Customers . WHERE customer_id IN ( SELECT customer_id.

The objective of this SQL Server tutorial is to teach you how to use a SUBQUERY in a SQL statement to expand the scope of operation of the statement and to narrow its focus with respect to the output and get more specific output. What is SUBQUERY in SQL Server? A SUBQUERY is a SQL query within a SQL statement.

Apr 11, 2025 · Nested queries, also known as subqueries, are an essential tool in SQL for performing complex data retrieval tasks. They allow us to embed one query within another, enabling us to filter, aggregate, and perform sophisticated calculations.

Dec 28, 2023 · In SQL Server, Subqueries are a powerful feature used to perform complex queries and combine data from multiple tables or multiple data sets. Subqueries can be used in different business cases and in different scenarios to …

Mar 25, 2025 · We can use subqueries in SELECT, INSERT, UPDATE, and DELETE statements as well as WHERE, FROM, and HAVING clauses. Subqueries allow users to break complex queries into smaller, more manageable parts. This makes it easier to retrieve and manipulate data in a structured way.