TOUNIXTIMESTAMP

Syntax

TOUNIXTIMESTAMP(datetime)

Purpose

This function converts a datetime expression datetime to a Unix timestamp (the number of seconds since '1970-01-01 00:00:00' UTC). If the parameter is of the DATE type, the time part is by default set to midnight (00:00:00).

Examples

1. Enable the ClickHouse extension function mode.

   obclient> ALTER SYSTEM SET sql_func_extension_mode = "ClickHouse";
   

2. Return an integer timestamp.

   obclient> SELECT TOUNIXTIMESTAMP('2026-03-30 12:00:00');
   

   The return result is as follows:

   +----------------------------------------+
   | TOUNIXTIMESTAMP('2026-03-30 12:00:00') |
   +----------------------------------------+
   |                             1774843200 |
   +----------------------------------------+
   1 row in set
   

3. Return the Unix timestamp for midnight of the current day.

   obclient> SELECT TOUNIXTIMESTAMP(DATE '2026-03-30');
   

   The return result is as follows:

   +------------------------------------+
   | TOUNIXTIMESTAMP(DATE '2026-03-30') |
   +------------------------------------+
   |                         1774800000 |
   +------------------------------------+
   1 row in set