Question

I wasn’t sure what could be the title for my question so sorry about that.

I’m trying to write a SQL query to achieve the no. of members who should get reimbursed from a pharmacy.

For example : I went to pharmacy, I took a vaccine but by mistake I paid from my pocket. so now Pharmacy needs to reimburse me that amount. Lets say I have the data like:

MemberId  Name       ServiceDate    PresNumber    PersonId    ClaimId  AdminFee(in $)

   1      John        1/1/2011           123        345          456         0 
   1      John        1/21/2011          123        345          987        20
   2      Mike        2/3/2011           234        567          342         0
   2      Mike        2/25/2011          234        567          564        30
   5      Linda       1/4/2011           432        543          575         0
   5      Linda       4/6/2011           987        543          890         0
   6      Sonia       2/6/2011           656        095          439         0

This data shows all members from that pharmacy who got reimbursed and who haven’t.

I need to find out the member having AdminFee 0 but i also need to check another record for the same member having same PresNumber, same PersonId where the ServiceDate falls within 30 Days of the Original Record.
If another record meets this criteria and the AdminFee field contains a value (is NOT 0) then it means that person has already been reimbursed. So from the data you can see John and Mike have already been reimbursed and Linda and Sonia need to be reimbursed.

Can anybody help me how to write an SQL query on this?

Answer 1

You don’t mention what SQL engine you’re using, so here is some generic SQL. You’ll need to adapt the date math and the return of True/False ( in the second option) to whatever engine you’re using:

 -- Already reimbursed
 SELECT * FROM YourTable YT1 WHERE AdminFee = 0 AND EXISTS 
     (SELECT * FROM YourTable YT2 
        WHERE YT2.MemberID = YT1.MemberID AND 
              YT2.PresNumber = YT1.PresNumber AND
              YT2.ServiceDate >= YT1.ServiceDate - 30 AND 
              AdminFee > 0)

 -- Need reimbursement
 SELECT * FROM YourTable YT1 WHERE AdminFee = 0 AND NOT EXISTS 
     (SELECT * FROM YourTable YT2 
        WHERE YT2.MemberID = YT1.MemberID AND 
              YT2.PresNumber = YT1.PresNumber AND
              YT2.ServiceDate >= YT1.ServiceDate - 30 AND 
              AdminFee > 0)

or

 -- Both in one.
 SELECT YT1.*, 
   CASE WHEN YT2.MemberID IS NULL THEN False ELSE True END AS AlreadyReimbursed 
   FROM YourTable YT1 JOIN YourTable YT2 ON 
      YT1.MemberID = YT2.MemberID AND 
      YT1.PresNumber = YT2.PresNumber AND 
      YT1.ServiceDate <= YT2.ServiceDate + 30 
    WHERE YT1.AdminFee = 0 AND YT2.AdminFee > 0)