PROC SQL allows a subquery (contained in parentheses) at any point in an expression where a simple column value or constant can be used. In this case, a subquery must return a single value, that is, ...

SQL queries can get complex. For example, you might have been a little thrown off by the many to many join in the last lab. There, you had to join four tables. This is just the tip of the iceberg.

Technical Lesson: SQL Subqueries A subquery, also known as a nested query or inner query, is an SQL query that is embedded within another SQL query. The primary purpose of a subquery is to enable ...