Oracle数据去重

Oracle数据去重保留一条

 

多个条件分组

  delete from M_BASEPRICE_0719_CC m  where (m.brand_code,m.supplier_code,m.part_code_m)  in  (select brand_code,supplier_code,part_code_m
                     from M_BASEPRICE_0719_CC group by brand_code,supplier_code,part_code_m having count(*) > 1)
                     and rowid not in (select min(rowid)
                       from M_BASEPRICE_0719_CC
                      group by brand_code,supplier_code,part_code_m
                     having count(*) > 1);

 

单个条件分组

          delete from  M_BASEPRICE_JL m  where m.part_code_m  in  (select part_code_m
                     from M_BASEPRICE_JL group by part_code_m having count(*) > 1)
                     and rowid not in (select min(rowid)
                       from M_BASEPRICE_JL
                      group by part_code_m
                     having count(*) > 1); 

注意：多个条件分组的in前后必须是多个条件，不然会多删，血的教训，假如几百万条数据，删多了再补就很麻烦的