Read this SQL tutorial to learn when to use SELECT, JOIN, subselects and UNION to access multiple tables with a single statement ... UNION and subqueries. SEE: Take advantage of these quick ...

the PROC SQL query with the Pass-Through subquery performs better. (The STIMER option on the PROC SQL statement provides statistics on the SAS System's process.) SAS Log Comparing the Two PROC SQL ...

select ‘true’ from dual where 1 is null; select ‘true’ from dual where null is null; When you use IN, you’re telling SQL ... ANY IN clause compares values returned by the subquery ...