By: Rick Dobson
Overview
A subquery is a select statement embedded in another SQL statement, such as a select, insert, delete, or update statement. The set of value(s) returned by the inner select statement are passed to the outer SQL statement. The inner select statement is always embraced in parentheses. The result set from the inner select statement is an example of a temporary data store. Subqueries can reside at many different places within an outer select statement. This tutorial section introduces the topic of subqueries by presenting easy-to-follow code samples that demonstrate the use of subqueries in where clauses, select list items, and with insert, update, and delete statements. Two subsequent sections drill down on more advanced issues pertaining to subqueries.
In this section we will cover the following topics:
- Using a subquery in a select statements where clause
- Using a subquery as a select list item
- Using a subquery in insert, update, and delete statements
Additional Information
Here are some links to resources that you may find useful to help you grow your understanding of content from this section of the tutorial.
- Introduction to Subqueries in SQL Server
- SQL Server Subquery
- SQL Subqueries
- SQL - Sub Queries
- Using Subqueries in the Select Statement
- Inserting records using subqueries
- SQL update using subqueries
- SQL Delete records using subqueries
