unaryExpression

unaryExpression(operator: Integer;
                operand:  Object io;
                level:    Integer): Object;

The unaryExpression method of the JadeRelationalQueryProviderIF interface is called by the ODBC driver to allow the application to map a search predicate in the form of an expression tree onto its own internal representation. The only unary operator is Op_Not applied to a Boolean value.

If the implementation cannot represent the expression, it can return the null value, which instructs the ODBC driver to default to its own query execution plan.

The depth of the expression tree is indicated by the value of the level parameter.