I am attempting to join two datasets in JMP using a unique identifier plus a closest date match. I have some code here that runs and is pretty close to what I need but I am having trouble with it keeping many to one matches. One unique identifier "EMP_ID_UID" could (or could not) have several "Transaction Dates" and multiple "MED_SCAN_DTIMES" will match one "Transaction Date" (because Transaction Date is a date that someone clocked in for their shift and naturally a busy provider will likely administer more than one medication during a 12 hour shift). So what I need is for the join to FIRST match on "EMP_ID_UID" and THEN match the "MED_SCAN_DTIME" to the most recent "Transacation Date" and for it to allow many "MED_SCAN_DTIME" to match a single "Transaction Date." Right now, the code below matches the EMP_ID_UID and it does allow many transaction dates to match one EMP_ID_UID. It also matches the closest dates BUT it will only allow one to one match of the dates. It keeps the closest match only. Is there a modification I can make on the join code that produce what I need? Any thoughts or assistance will be greatly appreciated ! Thank you!
SELECT * FROM "Random Sample Trial" t1 LEFT OUTER JOIN "Subset of Relevent Unit Org Codes ONLY" t2 ON t1.EMP_ID_UID = t2.EMP_ID_UID AND t1.MED_SCAN_DTIME>t2.TransactionDate WHERE t1.MED_SCAN_DTIME > t2.TransactionDate GROUP BY t1.EMP_ID_UID,t1.MED_SCAN_DTIME HAVING abs(t1.MED_SCAN_DTIME-t2.TransactionDate)=min(abs(t1.MED_SCAN_DTIME-t2.TransactionDate)) ORDER BY t1.EMP_ID_UID ; quit;