Can't change date format SQL

Question

I have the current date format [DD_MM_YYY] in a column on my table and would like to change it to [YYYY_MM_DD]. Can't seem to figure out the correct syntax.

Answer 1

This one should do for date fields:

SELECT DATE_FORMAT(NOW(), '%Y-%m-%d');

Answer 2

You can use the convert function in sql.

SELECT CONVERT (data_type(length)),Date, DateFormatCode)

To convert in this format [YYYY_MM_DD] if the date format is in varchar:

Select CONVERT(varchar,column_name,23)

Answer 3

If you are using Exasol, you can use to_date():

select to_date(datecoll, 'DD_MM_YYYY')

I would recommend leaving this as a date. But if you want to convert this back to a string:

select to_char(to_date(datecoll, 'DD_MM_YYYY'), 'YYYY-MM-DD')