Other special values besides NULL?
Are there other special values like NULL in Vertica SQL ?
NULL is nice in that data columns of any type can have NULL values.
We can interpret NULL as the concept of "N/A" (i.e. missing, not available, not asked, not answered, etc.).
I would also like to represent another concept, the idea of
Overall, in the same result set.
Is there another special value that I can return in a query, other than NULL, but which like NULL:
- can be returned in any type of column integer, float, string, date, etc.
- doesn't match any actual finite value that might be in the data
- doesn't throw
ERROR: For 'UNION', types varchar and numeric are inconsistentin this toy query:
select 1 as numeral, 'one' as name union all select 2 as numeral, 'two' as name union all select NULL as numeral, NULL as name union all select ??? as numeral, ??? as name;