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select version();
| version() |
|---|
| 8.0.27 |
create table t
(dt varchar(10));
insert into t values
('1/1/2020'),('2020/1/12'),('12/12/12'),(null),('13-14-15');
select dt,
case when length(substring_index(dt,'/',-1)) = 4 then str_to_date(dt,'%d/%m/%Y')
when length(substring_index(dt,'/',1)) = 4 then str_to_date(dt,'%Y/%m/%d')
when length(substring_index(dt,'/',1)) = 2 then str_to_date(dt,'%y/%m/%d')
else str_to_date(dt,'%y/%m/%d')
end dateformatted
from t;
| dt | dateformatted |
|---|---|
| 1/1/2020 | 2020-01-01 |
| 2020/1/12 | 2020-01-12 |
| 12/12/12 | 2012-12-12 |
| null | null |
| 13-14-15 | null |