Re:SQL: 2023 is finished: Here is what's new
by SoftTalker on Friday April 14, 2023 @12:58PM
(#35571778)
No ideally not. If they are they must be ignored.
If other columns in the row index are unique regardless of the value of the nullable column, then the row is logically unique. So if in that case the NULL value is ignored, then OK. But two NULLs neither match each other nor are they distinct from each other. You just cannot say either way.
If other columns in the row index are unique regardless of the value of the nullable column, then the row is logically unique. So if in that case the NULL value is ignored, then OK. But two NULLs neither match each other nor are they distinct from each other. You just cannot say either way.