Hi Jagadish, Thank you so much for the sample data and explanation. I understood the point of overlapping . Here comes the case for which the purpose is to identify overlapping and duplicate entries for the AE data. Comparison of overlapping events (AE#1 term = AE#2 term) when AE # <1> start date <= AE # <2> start date <= AE #<1> end date. What i am assuming is to flag or to list those records having overlapping events and small correction ae#1 term and ae#term suppose if they are same events , then also is the case overlapping events ? Previously i did flagging only those records with overlapping dates but where as the task required is comparison of overlapping events. So now how can i proceed with this ? Besides, i am also not able to understand what logic can i use for Comparison of overlapping events (AE#1 term = AE#2 term) when AE # <1> start date <= AE # <2> start date <= AE #<1> end date. Also please let me know what can i do for if the dates are missing . Like for some ending dates are missing where just the start dates are there !! Example : suppose 101 01JAN2004 02JAN2004 Headache 101 02JAN2004 03FEB2004 Back Pain 102 03NOV2003 10DEC2003 Rash 102 10NOV2003 10JAN2004 Abdominal Pain 102 04APR2004 06APR2004 Constipation 102 05 july2004 07 july2004 Back pain 102 05APR2004 07APR2004 Constipation 102 04APR2004 04APR2004 Headache Thanks in Advance !! Nandini.
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