Presto SQL：TO_UNIXTIME

Question

I want to convert a readable timestamp to UNIX time.

For example: I want to convert 2018-08-24 18:42:16 to 1535136136000 .

Here is my syntax:

    TO_UNIXTIME('2018-08-24 06:42:16') new_year_ut

My error is:

   SYNTAX_ERROR: line 1:77: Unexpected parameters (varchar(19)) for function to_unixtime. Expected: to_unixtime(timestamp) , to_unixtime(timestamp with time zone)

Answer 1

You need to wrap the varchar in a CAST to timestamp:

to_unixtime(CAST('2018-08-24 06:42:16' AS timestamp)) -- note: returns a double

If your timestamp value doesn't have fraction of second (or you are not interested in it), you can cast to bigint to have integral result:

CAST(to_unixtime(CAST('2018-08-24 06:42:16' AS timestamp)) AS BIGINT)

If your readable timestamp value is a string in different format than the above, you would need to use date_parse or parse_datetime for the conversion. See https://trino.io/docs/current/functions/datetime.html for more information.

Note: when dealing with timestamp values, please keep in mind that: https://github.com/trinodb/trino/issues/37