A table-expression is a SELECT statement. It is the fundamental building block of most SQL procedure statements. You can combine the results of multiple table-expressions with set operators, which ...

PROC SQL performs set operations even if the tables or views that are referred to in the table-expressions do not have the same number of columns. The reason for this is that the ANSI Standard for SQL ...

This is recursion in action. Different DBMS products implement recursive SQL in different ways. Recursion is implemented in standard SQL-99 using common table expressions (CTEs). DB2, Microsoft SQL ...