Read this SQL tutorial to learn when to use SELECT, JOIN, subselects and UNION to access multiple tables with a single statement.

Modifies a column's values in existing rows of a table or view. Restriction: You cannot use UPDATE on a table accessed via an engine that does not support UPDATE processing. You can update one or more ...

Therefore, special consideration should be used when the names of DBMS objects, such as tables and columns, are used with SAS/ACCESS and the SQL Procedure Pass-Through Facility. See your DBMS chapter ...