- "Generates an SQL expression from the given keywords. Valid
-combinations of the arguments are: string; table; table and alias;
-table and attribute; table, attribute, and type; table or alias, and
-attribute; table or alias, and attribute and type; attribute; and
-attribute and type."
+ "Returns an SQL expression constructed from the supplied arguments
+which may be combined as follows: ATTRIBUTE and TYPE; ATTRIBUTE;
+ALIAS or TABLE and ATTRIBUTE and TYPE; ALIAS or TABLE and
+ATTRIBUTE; TABLE, ATTRIBUTE and TYPE; TABLE and ATTRIBUTE; TABLE
+and ALIAS; TABLE; and STRING."