Depends on which kind you're looking for.
The current integer Unix Timestamp (1350517005) can be retrieved like so:
SELECT UNIX_TIMESTAMP();
MySQL often displays timestamps as date/time strings. To get one of those, these are your basic options (from the MySQL Date & Time reference):
SELECT CURRENT_TIMESTAMP;
SELECT CURRENT_TIMESTAMP();
SELECT NOW();
Answer from Brad Koch on Stack OverflowDepends on which kind you're looking for.
The current integer Unix Timestamp (1350517005) can be retrieved like so:
SELECT UNIX_TIMESTAMP();
MySQL often displays timestamps as date/time strings. To get one of those, these are your basic options (from the MySQL Date & Time reference):
SELECT CURRENT_TIMESTAMP;
SELECT CURRENT_TIMESTAMP();
SELECT NOW();
CURRENT_TIMESTAMP is standard SQL and works on SQL server, Oracle, MySQL, etc. You should try to keep to the standard as much as you can.
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For MySQL (5.6+) you can do this:
SELECT ROUND(UNIX_TIMESTAMP(CURTIME(4)) * 1000)
Which will return (e.g.):
1420998416685 --milliseconds
To get the Unix timestamp in seconds in MySQL:
select UNIX_TIMESTAMP();
Details: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#function_unix-timestamp
Not tested PostgreSQL, but according to this site it should work: http://www.raditha.com/postgres/timestamp.php
select round( date_part( 'epoch', now() ) );