How to group results by day in SQL query?

Question

MySQL

Hello.
There is a table, in it a field with date and time Ymd H:i:s
Task: it is necessary to return the grouped data of a field with date on days|hours|months.
What is the best way to do this?

Answer 1

Hello.
The request will be something like this, if I understand correctly.

SELECT t.field1, t.field2 FROM table AS t
WHERE condition
GROUP BY DAYOFMONTH(t.date), HOUR(t.date), MONTH(t.date)

Answer 2

DATE_FORMAT + GROUP BY

Answer 3

Hourly:
SELECT ... FROM table AS t WHERE ...
GROUP BY DATE(t.date), HOUR(t.date) Daily
:
SELECT ... FROM table AS t WHERE ...
GROUP BY DATE(t .date)
By month:
SELECT ... FROM table AS t WHERE ...
GROUP BY YEAR(t.date), MONTH(t.date)