subtraction of 2 select statements

I have a simple table:

Neighbourhood

 code neighbourhood country

Some countries have the same neighborhood name. All I want is the total minus the distinct. but I have a problem with the operator; Here is what I am doing.

 select count(*)- select distinct(neighbourhood) from Neighbourhood

Answer

So you want:

select count(*) - count(distinct neighbourhood)
from Neighbourhood;

I might suggest a further breakdown:

select cnt, count(*), min(neighbourhood), max(neighbourhood)
from (select neighbourhood, count(*) as cnt
      from neighbourhood
      group by neighbourhood
     ) n
group by cnt
order by cnt;

This shows the frequency of duplication along with example value of neighbourhood.