Scalar Functions

date_truc

date_trunc(‘interval’, timestamp)

The date_trunc function truncates given timestamp down to the given interval.

Truncation is based on UTC time zone since Crate Data stores timestamps as UTC milliseconds since the epoch.

Valid values for interval are:

  • second
  • minute
  • hour
  • day
  • week
  • month
  • quarter
  • year

The following example shows how to use the date_trunc function to generate a day based histogram:

cr> select date_trunc('day', date) as day, count(*) as num_locations
... from locations
... group by date_trunc('day', date)
... order by date_trunc('day', date)
+---------------+---------------+
| day           | num_locations |
+---------------+---------------+
| 308534400000  | 4             |
| 1367366400000 | 1             |
| 1373932800000 | 8             |
+---------------+---------------+
SELECT 3 rows in set (... sec)

Note

Currently scalar functions, such as date_trunc, can only be used in the GROUP BY clause.