Subqueries Archives

Subqueries provide a powerful means to combine data from one or more table into one result. They are sometimes called nested queries. As the name implies, they one or more queries, one inside one another other.

IF you’re unfamiliar them, then your first order of business should be to read our article Introduction to Subqueries. This is super place to start.

They can be used in many places throughout the SELECT statement.

All the examples for this lesson are based on Microsoft SQL Server Management Studio and the sample databases AdventureWorks and WideWorldImporters. You can get started using these free tools using my guide Getting Started Using SQL Server

How to use the IN Operator with a SubQuery

In this video we’ll walk you though how to use the IN operator with a Subquery; we’ll show you why you would want to use IN with a subquery. In it’s simplest form the IN statement matches a column values to a list. TRUE is returned if there is a match. A main advantage of […]

Joins versus Subqueries SQL Puzzle

In this puzzle, we’re going to learn about joins versus subqueries. In many queries you can substitute joins and subqueries. Yet, since each has their strengths, it isn’t wise to do so. Once you have worked through this puzzle you see some of the benefits and disadvantages of joins versus subqueries. Solving puzzles is a […]

Subqueries versus Joins

Joins and subqueries are both be used to query data from different tables and may even share the same query plan, but there are many differences between them. Knowing the differences and when to use either a join or subquery to search data from one or more tables is key to mastering SQL. All the examples […]

Is it possible to use Joins, Subqueries, and Unions in one Query?

A reader recently asked me to help them solve a problem combining data from multiple tables into a single result. What was interesting was that the solution used the three ways to combine data that we have recently covered, namely: JOINS, set operators, and subqueries. Given the comprehensive nature of this problem I thought it […]

Get Ready to Learn SQL Server 23: Using Subqueries in the HAVING Clause

This is the fifth in a series of articles about subqueries. In this article we discuss subqueries in the HAVING clause. Other articles discuss their uses in other clauses. All the examples for this lesson are based on Microsoft SQL Server Management Studio and the AdventureWorks2012 database. You can get started using these free tools using […]

Using A Subquery in the FROM clause

This is the fourth in a series of articles about subqueries. In this article we discuss using a subquery in the FROM clause. Other articles discuss their uses in other clauses. All the examples for this lesson are based on Microsoft SQL Server Management Studio and the AdventureWorks2012 database. You can get started using these free tools […]

Using Subqueries in the WHERE Clause

This is the third in a series of articles about subqueries. In this article we discuss subqueries in the WHERE clause. Other articles discuss their uses in other clauses. All the examples for this lesson are based on Microsoft SQL Server Management Studio and the AdventureWorks2012 database. You can get started using these free tools […]

Using Subqueries in the Select Statement

This is the second in a series of articles about subqueries. In this article we discuss subqueries in the SELECT statement’s column list. Other articles discuss their uses in other clauses. All the examples for this lesson are based on Microsoft SQL Server Management Studio and the AdventureWorks2012 database. You can get started using these […]

Subqueries – Introduction to a Subquery in SQL

The purpose of this article is to introduce you to subqueries and some of their high-level concepts. There are a lot of details to cover in order to learn sub queries, but you’ll see we cover those in depth in later articles. All the examples for this lesson are based on Microsoft SQL Server Management […]