SQL: Use distinct on groups of similar data -
hello mates have following problem in vertica database: have large table
+------+------+------+ | date | col1 | col2 | +------+------+------+ | 1 | | b | | 2 | | b | | 3 | d | e | | 2 | c | d | | 1 | c | d | +------+------+------+
as can see have redundant data, taken on different dates (row 1 & 2 , row 4 & 5). table removes redundant data deleting rows lower date, giving me result that:
+------+------+------+ | date | col1 | col2 | +------+------+------+ | 2 | | b | | 2 | c | d | | 3 | d | e | +------+------+------+
using distinct not work since delete rows randomly not considering date, might end table this:
select distinct col2, col3 table +------+------+------+ | date | col1 | col2 | +------+------+------+ | 2 | | b | | 1 | c | d | | 3 | d | e | +------+------+------+
which not desired.
is there anyway accomplish that? mates
do group by
on 2 columns , aggregate on highest date:
select max(date), col1, col2 table group col1, col2
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