Question

I’m stumped with this query. I have a deal table with deals for different doctors. There is a many to many between deals and doctors (more than one doctor per deal is possible). I need to find the deals with the closest doctors to a given user’s latitude and longitude. I have a stored procedure that takes care of finding the distance.

    Select d.dealID, do.doctorID,
    dbo.fn_latlongdist($userlat,$userlong,do.doctorLatitude,do.doctorLongitude) as distance
    From y_Deals d
    JOIN y_deals_doctor dd ON dd.dealID = d.dealID
    JOIN Doctor do on dd.doctorID = do.doctorID 
    ORDER BY distance

Now I want to group by the dealID so I don’t return multiple deals. Problem is I want to return the doctorID with the minimum distance. Doesn’t seem like there’s any aggregate function that would surround doctorID that would return the doctorID with the minimum distance column.

How should I approach this?

Answer 1

See if this works for you

Select * From
(
    Select
          d.dealID
        , do.doctorID
        , dbo.fn_latlongdist($userlat, $userlong, do.doctorLatitude, do.doctorLongitude) as Distance
        , ROW_NUMBER() OVER (PARTITION BY d.dealID ORDER BY dbo.fn_latlongdist($userlat, $userlong, do.doctorLatitude, do.doctorLongitude)) AS RowNumber
    From
        y_Deals d
    JOIN
        y_deals_doctor dd ON dd.dealID = d.dealID
    JOIN
        Doctor do on dd.doctorID = do.doctorID 
) T
Where
    T.RowNumber = 1

UPDATE:

;With AllData As
(
    Select
          d.dealID
        , do.doctorID
        , dbo.fn_latlongdist($userlat, $userlong, do.doctorLatitude, do.doctorLongitude) as Distance
        , ROW_NUMBER() OVER (PARTITION BY d.dealID ORDER BY dbo.fn_latlongdist($userlat, $userlong, do.doctorLatitude, do.doctorLongitude)) AS RowNumber
    From
        y_Deals d
    JOIN
        y_deals_doctor dd ON dd.dealID = d.dealID
    JOIN
        Doctor do on dd.doctorID = do.doctorID 
)
,DrCount As
(
    Select
          dealID
        , Count(Distinct doctorID) as doctorCount
    From
        AllData
    Group By
        dealID
)
Select
    *
From
    AllData A
Inner Join
    DrCount C
On
    A.dealID = C.dealID
Where
    A.RowNumber = 1