Hi ,Today We will discuss about DATE Functions in oracle.
DATE Related Functions:
1.CURRENT_DATE
The Oracle CURRENT_DATE function returns the current date in the session time zone.
syntax:
CURRENT_DATE
Example
SELECT
CURRENT_DATE
FROM
DUAL;
It will return the current date.
2.EXTRACT:
The Oracle EXTRACT() function extracts a specific component (year, month, day, hour, minute, second, etc.,) from a datetime or an interval value.
syntax:
EXTRACT(field FROM source)
Where,
Field is
> Year , Month , Day
> Hour , Minutes, Second
> Timezone hour , minute , region ,addr
Source is
> Date
> Interval
Example:
SELECT EXTRACT( MONTHFROMTO_DATE( '31-Dec-1999 15:30:20 ', 'DD-Mon-YYYY HH24:MI:SS' ) ) MONTH
FROM DUAL;
3. ADD_MONTHS:
Oracle ADD_MONTHS() function adds a number of month (n) to a DATE and returns the same day n of months away.
Syntax:
ADD_MONTHS(date_expression, month)
Example:
SELECT
ADD_MONTHS( DATE'2021-06-15', 1 )
FROM dual;
Output:
15-JUN-2021
4.LAST_DAY
The Oracle LAST_DAY() takes a DATE argument and returns the last day of the month of that date.
syntax:
The following illustrates the syntax of the Oracle LAST_DAY() function:
LAST_DAY(date)
Example:
SELECT
LAST_DAY(SYSDATE)
FROM dual;
5.NEXT_DAY
The Oracle NEXT_DAY() function returns the date of the first weekday specified by day name that is later than a date.
syntax:
The following illustrates the syntax of the Oracle LAST_DAY() function:
NEXT_DAY(date,weekday)
Example:
SELECT
NEXT_DAY( DATE'2021-06-16', 'SUNDAY' )
FROM dual;
Output:
20-JUN-2021
6.MONTHS_BETWEEN:
The Oracle MONTHS_BETWEEN() function returns the number of months between two dates.
syntax:
The following illustrates the syntax of the Oracle MONTHS_BETWEEN() function:
MONTHS_BETWEEN(minuend_date, subtrahend_date );
Example:
SELECT
MONTHS_BETWEEN( DATE'2021-07-01', DATE'2021-01-01' )
FROM DUAL;
Output:
6
7.TO_CHAR
The Oracle TO_CHAR() function converts a DATE or INTERVAL value to a string in a specified date format.
The Oracle TO_CHAR() function is very useful for formatting the internal date data returned by a query in a specific date format.
syntax:
TO_CHAR(expr [, date_format] [, nslparam]);
Example:
SELECT
TO_CHAR( sysdate, 'YYYY-MM-DD' )
FROM dual
Output:
16-JUN-2021
8.TO_DATE
The Oracle TO_DATE() function converts a date literal to a DATE value.
Syntax:
TO_DATE (string, format, nls_language)
Example:
SELECT TO_DATE( '16 Jun 2021', 'DD MON YYYY' )
FROM
dual;
Output:
16-JUN-2021
TIMESTAMP Related Functions:
CURRENT_TIMESTAMP
The Oracle CURRENT_TIMESTAMP function returns the current date and time in session time zone.
the CURRENT_TIMESTAMP function returns a value of TIMESTAMP WITH TIME ZONE while the CURRENT_DATE function returns a value of DATE without time zone data.
syntax:
CURRENT_TIMESTAMP
Example:
SELECT
CURRENT_TIMESTAMP
FROM
DUAL;
It will return the date with time of you current time zone.
LOCALTIMESTAMP
SELECT
LOCALTIMESTAMP, CURRENT_TIMESTAMP
FROM dual;
It will print local timestamp .
SYSTIMESTAMP
The Oracle SYSTIMESTAMP function returns a TIMESTAMP WITH TIME ZONE value that represents the system date and time including fractional seconds and time zone.
SELECT
SYSTIMESTAMP
FROM
dual;
TIMEZONE Related Functions:
DBTIMEZONE
The Oracle DBTIMEZONE function returns the database time zone value.
SELECT
DBTIMEZONE
FROM
dual;
SESSIONTIMEZONE
The Oracle SESSIONTIMEZONE function returns the time zone of the current session.
SELECT
SESSIONTIMEZONE
FROM
dual;
i will update remaining function later.
thank you for reading.