Question

I am trying to write a query and would like some help if possible. Thanks in advance.

I have a table of facility data (~100k rows) that I am getting from a public source. That data contains several records for what I would consider to be the same place (same name, city, state), they just have different suite numbers. The other interesting bit of code is that I have a selection counter on the data that I increment anytime someone chooses one of the facilities. This way, I can use the selection count along with some other weight calculations to make results show higher in a list.

What I am trying to do is write a query that when someone enters a search query, it will show only one record for the facility, the one with the highest selection count, and omit the rest.

Note: I do not want to do any preprocessing to the data as it is going to get re-loaded monthly.

Scheama:
ID
Name
Address 1
Address 2
City
State
Zip
Phone
Selection Count

Example Search: “women”

ID  Name                        City        State   Selection Count
1   Brigham & Women's Hospital  Boston      MA      22
2   Brigham & Women's Hospital  Cambridge   MA      0
3   Brigham & Women's Hospital  Boston      MA      5
4   Brigham & Women's Hospital  Boston      MA      1
5   Brigham & Women's Hospital  Orlando     FL      3
6   Woman's Hospital of Detroit Detroit     MI      100
7   Brigham & Women's Hospital  Boston      MA      0
8   Woman's Hospital of Detroit Detroit     MI      55

What I’d like is a resultset that contains 1, 2, 5, 6

1,3,4,7 Are the same so bring back the top selection count. Same for 6 and 8.

I am sure that there is a having and a top clause in here somewhere, but I have not been able to get this to do what I want.

Thoughts?

Answer 1

How about

select id, name, city, state, selcount from t 
where exists
(
  select 1 from
  (select name, city, state, max(selcount) selcount
     from t 
    group by name, city, state) s
  where s.name = t.name and s.city = t.city and s.state = t.state and s.selcount = t.selcount
)

I’ve built a SQL Fiddle for this to show a working example.