Hive Date Conversion Function 2

Turn arrogant God http://www.oratea.net/?p=944

No matter what data you do, you can't do without the use of date functions.

This reproduces the use of the date function of hive, which is quite complete.

Date function Unix timestamp to date function: From_unixtime syntax: From_unixtime (bigint unixtime[, string format])
return value: String
Description: Convert Unix timestamp (from 1970-01-01 00:00:00 UTC to the number of seconds in the specified time) to the time format of the current time zone
Example:
Hive> Select From_unixtime (1323308943, ' YyyyMMdd ') from dual;
20111208

Get current UNIX timestamp function: Unix_timestamp syntax: Unix_timestamp ()
return value: bigint
Description: Gets the UNIX timestamp for the current time zone
Example:
Hive> Select Unix_timestamp () from dual;
1323309615

Date to UNIX timestamp function: Unix_timestamp syntax: Unix_timestamp (string date)
return value: bigint
Description: Converts the date of the format to "Yyyy-mm-dd HH:mm:ss" to a UNIX timestamp. If the conversion fails, 0 is returned.
Example:
Hive> Select Unix_timestamp (' 2011-12-07 13:01:03 ') from dual;
1323234063

Specify format date to UNIX timestamp function: Unix_timestamp syntax: Unix_timestamp (string date, string pattern)
return value: bigint
Description: Converts the date of the pattern format to the Unix timestamp. If the conversion fails, 0 is returned.
Example:
Hive> Select Unix_timestamp (' 20111207 13:01:03 ', ' yyyyMMdd HH:mm:ss ') from dual;
1323234063

Date time to date function: To_date syntax: to_date (string timestamp)
return value: String
Description: Returns the date part in a DateTime field.
Example:
Hive> Select To_date (' 2011-12-08 10:03:01 ') from dual;
2011-12-08

Date following year function: Year Syntax: Year (string date)
return value: int
Description: Returns the year of the date.
Example:
Hive> Select year (' 2011-12-08 10:03:01 ') from dual;
2011
Hive> Select year (' 2012-12-08 ') from dual;
2012

Date-to-month function: Month Syntax: month (string date)
return value: int
Description: Returns the month of the date.
Example:
Hive> Select month (' 2011-12-08 10:03:01 ') from dual;
12
Hive> Select month (' 2011-08-08 ') from dual;
8

Date the following day function: Time Syntax: Days (string date)
return value: int
Description: Returns days in the date.
Example:
Hive> Select Day (' 2011-12-08 10:03:01 ') from dual;
8
Hive> Select Day (' 2011-12-24 ') from dual;
24

Date-to-hour function: Hour Syntax: Hour (string date)
return value: int
Description: Returns the hour in the date.
Example:
Hive> Select Hour (' 2011-12-08 10:03:01 ') from dual;
10

Date-to-minute function: Minute Syntax: Minute (string date)
return value: int
Description: Returns the minute of the date.
Example:
hive> Select minute (' 2011-12-08 10:03:01 ') from dual;
3

Date to seconds function: Second syntax: second (string date)
return value: int
Description: Returns the seconds in the date.
Example:
Hive> Select Second (' 2011-12-08 10:03:01 ') from dual;
1

Date-to-week function: WeekOfYear syntax: WeekOfYear (string date)
return value: int
Description: Returns the number of days in the current week.
Example:
Hive> Select WeekOfYear (' 2011-12-08 10:03:01 ') from dual;
49

Date comparison function: DateDiff syntax: DateDiff (String enddate, String startdate)
return value: int
Description: Returns the number of days from the end date minus the start date.
Example:
Hive> Select DateDiff (' 2012-12-08 ', ' 2012-05-09 ') from dual;
213

Date increment function: Date_add syntax: Date_add (string startdate, int days)
return value: String
Description: Returns the date that the start date startdate increased days.
Example:
Hive> Select Date_add (' 2012-12-08 ', ten) from dual;
2012-12-18

Date reduction function: Date_sub syntax: Date_sub (string startdate, int days)
return value: String
Description: Returns the date that the start date startdate reduced days.
Example:
Hive> Select Date_sub (' 2012-12-08 ', ten) from dual;
2012-11-28

Hive Date Conversion Function 2