HOUR() and FROM_DAYS() function in MariaDB

1. HOUR() Function :
In MariaDB, the HOUR() function is used to return the hour portion of a date value. In this function, the first parameter will be date_value. This function will return HOUR part of the given date. Since a time value can be range from -838:59:59′ to ‘838:59:59’ so that this function can return values 0 to up to 838.

Syntax :

HOUR(date_value)

Parameter :

• date_value – A DateTime value from which hour portion will be extracted.

Returns : The Hour part from a date.

Example-1 :

SELECT HOUR('2020-05-09 06:11:18.000004');

Output :

6

Example-2 :

SELECT HOUR('837:56:52');

Output :

837

Example-3 :

SELECT HOUR('2018-02-11 11:19:01');

Output :

11

Example-4 :

SELECT HOUR('10:02:06');

Output :

10

Example-5 : Current system time is returned by the CURTIME() function.

SELECT HOUR(CURTIME());

Output :

8

2. FROM_DAYS() Function:
In MariaDB, the FROM_DAYS() function is used to convert a numeric day into a date value. In this function, the first parameter will be a date. This function will convert a given numeric to date. This function is to be used only with dates within the Gregorian calendar.

Syntax :

FROM_DAYS(date)

Parameter :

• date – date(numeric) which will be converted in date value.

Returns : The date value.

Example-1 :

SELECT FROM_DAYS(735919) ;

Output :

'2014-11-17'

Example-2 :

SELECT (FROM_DAYS(780500)- FROM_DAYS(780500));

Output :

0

Example-3 :

SELECT FROM_DAYS(735910);

Output :

'2014-11-08'