So fügen Sie eine Sequenznummer für Gruppen in einer SQL-Abfrage ohne temporäre Tabellen hinzu

Beispieldaten

create table sometable([group] varchar(10), id int, somedata int)
insert sometable select 'Horses', 9, 11
insert sometable select 'chickens', 19, 121
insert sometable select 'Horses', 29, 123
insert sometable select 'chickens', 49, 124
insert sometable select 'Cows', 98, 1
insert sometable select 'Horses', 99, 2

Abfrage

select
    Record = ROW_NUMBER() over (order by [Group], id),
    [Group],
    GroupSequence = DENSE_RANK() over (order by [Group])
from sometable

Ausgabe

Record               Group      GroupSequence
-------------------- ---------- --------------------
1                    chickens   1
2                    chickens   1
3                    Cows       2
4                    Horses     3
5                    Horses     3
6                    Horses     3