Determine the person with the fewest entries - sql

Question

That seems to be quite simple, but there is no solution right now. I would like to determine from a table the person who has the least entries. If there are several, I just want to limit it to TOP 1.
In this example it would be Person 2 (or Person 5) with the least entries.
Id, Person
1, Person 1
2, Person 3
3, Person 4
4, Person 1
5, Person 1
6, Person 3
7, Person 2
8, Person 5
9, Person 6

Answer 1

Use GROUP BY and ORDER BY:
select top (1) person
from t
group by person
order by count(*);
The question specifically asks for one row in the result set. If you want all of them, then use top (1) with ties`.

Answer 2

Use aggregation and TOP:
SELECT TOP 1 person
FROM mytable
GROUP BY person
ORDER BY COUNT(*), person
This will give you a unique record with the name of the person that has fewest entries. If there are ties, the person with the alphabetically first name will show up.
Demo on DB Fiddle with your sample data:
| person |
| :------- |
| Person 2 |

Answer 3

You can also use
SELECT TOP 1 Person -- You can add WITH TIES too
FROM
(
SELECT Person, COUNT(Person) Cnt
FROM
(
VALUES
(1, 'Person 1'),
(2, 'Person 3'),
(3, 'Person 4'),
(4, 'Person 1'),
(5, 'Person 1'),
(6, 'Person 3'),
(7, 'Person 2'),
(8, 'Person 5'),
(9, 'Person 6')
) T(ID, Person)
GROUP BY Person
) TT
ORDER BY Cnt;
Demo
You could also use OFFSET and FETCHif you have 2012+ version as
SELECT Person
FROM
(
SELECT Person, COUNT(Person) Cnt
FROM
(
VALUES
(1, 'Person 1'),
(2, 'Person 3'),
(3, 'Person 4'),
(4, 'Person 1'),
(5, 'Person 1'),
(6, 'Person 3'),
(7, 'Person 2'),
(8, 'Person 5'),
(9, 'Person 6')
) T(ID, Person)
GROUP BY Person
) TT
ORDER BY Cnt
OFFSET 0 ROWS
FETCH NEXT 1 ROWS ONLY;