I want to delete the same data only the one with the largest datetime type in the ta field
where exists (select 1 from hahha t where t.ta=hahha.ta and t.ta > hahha.ta)
select * from hahha previously this condition can delete the value type, but now it is the time type
DELETE FROM hahha WHERE ta NOT IN
(
SELECT MAX(ta)
FROM hahha
GROUP BY tt,ts,tsb,tttt
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