This is an alternative to MaybeTable that doesn't use a tag columns. It's less flexible (no Functor or Applicative instance) and is meaningless when used with a table that has no non-nullable columns (so nesting NullTable is redundant). But in situations where the underlying Table does have non-nullable columns, it can losslessly converted to and from MaybeTable.
It is useful for embedding into a base table when you don't want to store the extra tag column in your schema.
This is an alternative to
MaybeTablethat doesn't use a tag columns. It's less flexible (noFunctororApplicativeinstance) and is meaningless when used with a table that has no non-nullable columns (so nestingNullTableis redundant). But in situations where the underlyingTabledoes have non-nullable columns, it can losslessly converted to and fromMaybeTable.It is useful for embedding into a base table when you don't want to store the extra tag column in your schema.