Three Use Case Examples for SQL Subqueries

There are many great tutorials on syntax, performance, and keywords for invoking subqueries. However, I wish to discover a tip highlighting selected SQL subquery use cases. Please briefly describe three SQL subquery use case examples. For each use case, cover how a subquery interacts with outer queries and the T-SQL for implementing the use case. Review excerpts from each example to show the value of implementing the use case.

The Derived Table

SQL Server Subquery in Select Statement with Where Clause

In this part of the temporary data store tip series we look at using subqueries to select data as well as how to use for inserts, updates and deletes.

Stairway to T-SQL: Beyond The Basics Level 3: Building a Correlated Subquery

This stairway level will expand on the subquery topic by discussing a type of subquery known as a correlated subquery, and explores what a correlated subquery is and how it is different from a normal subquery.

The Subquery

SubQuery

SubQuery

SubQuery