sql - how to find Duplicate records by comparing the previous records received in a table -
i have table
seq_num create_dt col1 col2 is_load 1 1/1/2014 b 2 2/1/2014 c d
3 3/1/2014 b
everyday data loaded table through loader. want write query should find duplicate data in current day record comparing previous days records , update column is_load = 'd'(as of duplicate) if duplicate record found.
so result should like
`seq_num create_dt col1 col2 is_load 1 1/1/2014 b 2 2/1/2014 c d 3 3/1/2014 b . .... . . . .... . . 11 11/3/2014 b d `
thanks in advance !!!!!
try this:
update mytable m set is_load = 'd' exists (select null mytable m.col1 = col1 , m.col2 = col2 , m.seq_num > seq_num);
this condition m.seq_num > seq_num
helps avoid setting first entry 'd'.
if matters can change seq_num
create_dt
can leave entries loaded same day.
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