T-SQL Fundamentals, Third Edition

Chapter 5. Table expressions

A table expression is a named query expression that represents a valid relational table. You can use table expressions in data-manipulation statements much like you use other tables. T-SQL supports four types of table expressions: derived tables, common table expressions (CTEs), views, and inline table-valued functions (inline TVFs). The focus of this chapter is on using SELECT queries against table expressions; Chapter 8, “Data modification,” covers modifications against table expressions.

Table expressions are not physically materialized anywhere—they are virtual. When you query a table expression, the inner query gets unnested. In other words, the outer query and the inner query are merged into one query directly ...