4 ms·

If multiple columns can only be null/non-null together it indicates a dependency which should be normalized.

• OJFord 4y ago
  Yes, but I was replying to 'no such thing as 1:1 relationships, just put it in the same table'.
  • bazoom42 4y ago
    But you are talking about 1:0..1 which is different from plain 1:1 relationships.