Oracle SQL 查寻,删除重复行，有则更新，无则插入

    MERGE INTO CRPROPTREND T1 USING DUAL T2    ON (T1.URIMD5="abc")    WHEN MATCHED THEN    INSERT　VALUES(...)    WHEN NOT MATCHED THEN    UPDATE SET ...;    

-- This query is not editable, but generally faster Select          URIMD5,         count(*)from     RUNPPV.CRPROPTRENDgroup by          URIMD5having   count(*) > 1-- This query is editable, but generally slower Select A1.*, A1.rowidfrom RUNPPV.CRPROPTREND A1 where exists (Select 'x' from RUNPPV.CRPROPTREND A2 where A1.URIMD5 = A2.URIMD5and A1.ROWID <> A2.ROWID)-- To delete all but one of each duplicate row, -- change the first line to 'Delete' -- and change the '<>' to '>' (keeps first duplicate) --                     or '<' (keeps last duplicate)