Generating a random timestamp in MySQL
Avishkar Autar · Sep 10 2013 · SQL
Random timestamps are fairly simple to generate and useful when creating test data or fake data for demos. The technique involves converting a MySQL timestamp into unix time, adding or subtracting a certain time range (in seconds), then converting back to a MySQL timestamp.
I’ve used this technique presented on underdog-projects.net before, where a starting timestamp is specified and a random time span is added to the timestamp. However, I wanted to try something slightly different and, in my opinion, a bit more robust. Instead of specifying a starting timestamp, I wanted a pivot timestamp from which a random time span is randomly added or subtracted.
SET @pivot_ts = '2013-01-15 22:15:45';
SET @max_span = 432000; /* 5 days in seconds */
SET @bias = SIGN(-0.5 + RAND());
UNIX_TIMESTAMP(@pivot_ts) + ( @bias * (FLOOR(RAND()*@max_span)) )
Of course all the variables can be made part of the SELECT statement to make everything more succient.