SQL Guide : Functions : Date time functions
  
Date time functions
Function
Purpose
ADD_MONTHS(expression, numeric-expression)
Returns a datetime value that represents expression plus a specified number of months.
expression specifies the starting date. The expression must return a value of one of the following built-in data types: a DATE or a TIMESTAMP.
numeric-expression returns a value of any built-in numeric data type. If the value is not of type INTEGER, it is implicitly cast to INTEGER before evaluating the function. The numeric-expression specifies the number of months to add to the starting date specified by expression. A negative numeric value is allowed.
CURDATE() CURRENT_DATE CURRENT DATE
Returns the current date
CURTIME()
CURRENT_TIME
CURRENT_TIME
Returns the current time
CURRENT_TIMESTAMP CURRENT TIMESTAMP
Returns the current date and time as a timestamp
DATE(expression)
Returns a date from a value.
The argument must be a DATE, TIMESTAMP, a positive number less than or equal to 3 652 059, or a valid string representation of a date or timestamp.
If the argument is a DATE, TIMESTAMP, or valid string representation of a date or timestamp, the result is the date part of the value.
If the argument is a string of length 7, it must represent a valid date in the form YYYYNNN, where YYYY are digits denoting a year, and NNN are digits between 001 and 366, denoting a day of that year.
If the argument is a number, the result is the date that is n-1 days after January 1, 0001, where n is the integral part of the number.
DAYNAME(date)
Returns a string with the day of the week
DAYOFMONTH(date)
Returns the day of the month as an integer between 1 and 31
DAYOFWEEK(date)
Returns the day of the week as an integer between 1 and 7, where 1 represents Sunday
DAYOFYEAR(date)
Returns the day of the year as an integer between 1 and 366
EXTRACT (date field FROM date_exp)
Isolates a single field of a datetime or a interval and converts it to a number.
HOUR(time_exp)
Returns the hour as an integer between 0 and 23
MINUTE(time_exp)
Returns the minute as an integer between 0 and 59
MONTH(date)
Returns the month as an integer between 1 and 12
MONTHNAME(date)
Returns the month name as a string
NOW()
Returns the current date and time as a timestamp
QUARTER(date)
Returns the quarter as an integer between 1 and 4
SECOND(time_exp)
Returns the second as an integer between 0 and 59
SYSDATE
Returns the current date and time as a timestamp
TIMESTAMPADD(interval, integer_exp, timestamp_exp)
Calculates a timestamp by adding integer_exp intervals of type interval to timestamp_exp
Keywords used to express valid TIMESTAMPADD interval values are:
SQL_TSI_FRAC_SECOND
SQL_TSI_SECOND
SQL_TSI_MINUTE
SQL_TSI_HOUR
SQL_TSI_DAY
SQL_TSI_WEEK
SQL_TSI_MONTH
SQL_TSI_QUARTER
SQL_TSI_YEAR
TIMESTAMPDIFF(interval, timestamp_exp1, timestamp_exp2)
Returns the integer number of intervals by which timestamp_exp1 is greater than timestamp_exp2
Keywords used to express valid TIMESTAMPADD interval values are:
SQL_TSI_FRAC_SECOND
SQL_TSI_SECOND
SQL_TSI_MINUTE
SQL_TSI_HOUR
SQL_TSI_DAY
SQL_TSI_WEEK
SQL_TSI_MONTH
SQL_TSI_QUARTER
SQL_TSI_YEAR
TIMESTAMP_FORMAT(input-string, format-string)
TO_DATE(input-string, format-string)
TO_TIMESTAMP(input-string, format-string)
Returns a timestamp that is based on the interpretation of the input string using the specified format. If the timestamp precision of timestamp-expression is less than what is specified by the format, zero digits are padded onto the right of the specified digits.
The following formats are supported:
YY Last two digits of the year (00-99)
YYYY 4-digit year (0000-9999)
RR behaves the same as YY
RRRR behaves the same as YYYY
MM Month (01-12)
DD Day of month (01-31)
HH24 Hour of the day (00-24) in 24-hour format
MI Minute (00-59)
SS Seconds (00-59)
FF or FFn Fractional seconds (0-999999999999).
The number n is used to specify the number of digits to include in the returned value. Valid values for n are 1-12 with no leading zeros.
Specifying FF is equivalent to specifying FF6.
The TO_DATE, TIMESTAMP_FORMAT, and TO_TIMESTAMP functions are synonymous.
WEEK(date)
Returns the week of the year as an integer between 1 and 52
YEAR(date)
Returns the year as an integer
See also
Functions