EXTRACT

The EXTRACT function extracts one field from a DATE, TIME, TIMESTAMP or INTERVAL expression. Returns BIGINT for all fields other than SECOND. For SECOND it returns DECIMAL(5,3) and includes milliseconds.

Syntax

EXTRACT(YEAR| MONTH| DAY| HOUR| MINUTE| SECOND FROM <datetime expression>| <interval expression>)

Examples

Function Result

EXTRACT(DAY FROM INTERVAL ‘2 3:4:5.678’ DAY TO SECOND) 2 | | EXTRACT(HOUR FROM INTERVAL ‘2 3:4:5.678’ DAY TO SECOND) 3 | | EXTRACT(MINUTE FROM INTERVAL ‘2 3:4:5.678’ DAY TO SECOND) 4 | | EXTRACT(SECOND FROM INTERVAL ‘2 3:4:5.678’ DAY TO SECOND) 5.678 | | EXTRACT(MINUTE FROM CURRENT_ROW_TIMESTAMP) where CURRENT_ROW_TIMESTAMP is 2016-09-23 04:29:26.234 29 | | EXTRACT (HOUR FROM CURRENT_ROW_TIMESTAMP)

where CURRENT_ROW_TIMESTAMP is 2016-09-23 04:29:26.234
4

### Use in Function
EXTRACT can be used for conditioning data, as in the following function which returns a 30 minute floor when [CURRENT_ROW_TIMESTAMP](/sql-reference-guide/built-in-functions/currentrowtimestamp/)  is input for *p_time*.
CREATE or replace FUNCTION FLOOR30MIN( p_time TIMESTAMP )
RETURNS  TIMESTAMP
CONTAINS SQL
RETURNS NULL ON NULL INPUT
RETURN  floor(p_time to HOUR) + (( EXTRACT (  MINUTE FROM p_time  ) / 30)* INTERVAL '30' MINUTE ) ;

You would implement this function using code along the following lines:

SELECT stream FLOOR30MIN( CURRENT_ROW_TIMESTAMP ) as ROWTIME, * from "MyStream" ) over (range current row ) as r

The code above assumes that you have previously created a stream called “MyStream.”