MD5 function returns empty result

Question

I am trying to return an MD5 encoded string of a value from my database, but it just returns a blank result (not null, just blank). I have tried just running this query and get the same result:

SELECT MD5('test');

I have tried restarting the MySQL server, MySQL Workbench, etc. But get the same result. If I try running the same command on a different database/server, it returns the hash string just fine.

What am I doing wrong? Is there a setting I disabled on accident?

Answer 1

Prior to MySQL v5.5.3, MD5() returned a binary string.

By default, MySQL Workbench does not display binary strings (to avoid accidental misinterpretation); however it is possible to display binary string values in output grids: View > Edit > Preferences > SQL Editor > Treat BINARY/VARBINARY as nonbinary character string.

Alternatively, either upgrade your MySQL server or transcode the result to a non-binary character set:

SELECT CONVERT(MD5('test') USING utf8)