Question

I’m trying to do something seemingly simple.

I want to return a column value (id) from a table person where the count of rows in persons = 1.

So something like :

SELECT Person.Id
FROM (select Count(*) from Person Having Count(*)=1);

But its not working.. Any help much appreciated.

Joe

Answer 1

select person.id from person where ((select count(*) from person) = 1)

you’ll get null if the the table is empty, or has more than one row.