> > > > For example: SELECT nullablecol FROM tab WHERE nullablecol = <value>; > > If the equality operator is strict then the nullablecol can be NULL in > the WHERE clause but not in the SELECT list. Tom's idea should allow > us to determine both of those things but your idea cannot tell them > apart, so, in theory at least, Tom's idea seems better to me. > > David >
That's really something I can't do, thanks for the explanation. -- Best Regards Andy Fan (https://www.aliyun.com/)
