The Data Virtuality Server supports the
EXCEPT set operations as a way of combining the results of query expressions.
queryExpression (UNION|INTERSECT|EXCEPT) [ALL] queryExpression [ORDER BY...]
- The output columns will be named by the output columns of the first set operation branch;
SELECTmust have the same number of output columns and compatible data types for each relative column. Data type conversion will be performed if data types are inconsistent and implicit conversions exist;
EXCEPTis specified without all, then the output columns must be comparable types;
INTERSECT ALL, and
EXCEPT ALLare currently not supported.