When a row is inserted into a table, SQL Server fills all columns in that row. All these columns are contaned in the 'inserted.*' construct. Some of these values are explicit, and some are implicit (NULL, identity, default value, computed value etc).

Here is an example:

create table #t

( id int identity,

a varchar(10),

b varchar(10) default 'hello',

c varchar(10),

computed_column as b + ' ' + c

)

insert #t (c)

output inserted.*

values ('test')

In the QOTD, the construct 'OUTPUT inserted.*' is equal to 'OUTPUT inserted.id, inserted.string'. 'Inserted.string' is an explicit column, while 'inserted.id' is an impilcit column.