Single-Row Functions (original) (raw)

Datetime functions operate on date (DATE), timestamp (TIMESTAMP, TIMESTAMP WITH TIME ZONE, and TIMESTAMP WITH LOCAL TIME ZONE), and interval (INTERVAL DAY TO SECOND, INTERVAL YEAR TO MONTH) values.

Some of the datetime functions were designed for the Oracle DATE data type (ADD_MONTHS, CURRENT_DATE, LAST_DAY, NEW_TIME, and NEXT_DAY). If you provide a timestamp value as their argument, then Oracle Database internally converts the input type to a DATE value and returns a DATE value. The exceptions are the MONTHS_BETWEEN function, which returns a number, and the ROUND and TRUNC functions, which do not accept timestamp or interval values at all.

The remaining datetime functions were designed to accept any of the three types of data (date, timestamp, and interval) and to return a value of one of these types.

All of the datetime functions that return current system datetime information, such as SYSDATE, SYSTIMESTAMP, CURRENT_TIMESTAMP, and so forth, are evaluated once for each SQL statement, regardless how many times they are referenced in that statement.

The datetime functions are:

• ADD_MONTHS
• CURRENT_DATE
• CURRENT_TIMESTAMP
• DBTIMEZONE
• EXTRACT (datetime)
• FROM_TZ
• LAST_DAY
• LOCALTIMESTAMP
• MONTHS_BETWEEN
• NEW_TIME
• NEXT_DAY
• NUMTODSINTERVAL
• NUMTOYMINTERVAL
• ORA_DST_AFFECTED
• ORA_DST_CONVERT
• ORA_DST_ERROR
• ROUND (date)
• SESSIONTIMEZONE
• SYS_EXTRACT_UTC
• SYSDATE
• SYSTIMESTAMP
• TO_CHAR (datetime)
• TO_DSINTERVAL
• TO_TIMESTAMP
• TO_TIMESTAMP_TZ
• TO_YMINTERVAL
• TRUNC (date)
• TZ_OFFSET