Read this SQL tutorial to learn when to use SELECT, JOIN, subselects and UNION to access multiple tables with a single statement. It’s sometimes difficult to know which SQL syntax to use when ...

The DICTIONARY tables component is specified in the FROM clause of a SELECT statement. DICTIONARY is a reserved libref for use only in PROC SQL. Data from DICTIONARY tables are generated at run time.

You can count and report the total number of rows that have the same value for one or more columns. You can use the automatic group by feature to group the values according to their columns. The ...