Nested select Statement Enhancements

Adaptive Server 15.7 expands the abilities of the asterisk (*).

In Adaptive Server 15.7 and later, you can use an asterisk in a nested select statement that is not an exists subquery as long as the asterisk:
In addition, you can:

When an asterisk resolves to a single table column for the nested query, the query is equivalent to explicitly using a single table column.

See "Queries: Selecting Data from a Table" in the Transact-SQL Users Guide.