How to get the drupal version using phpMyAdmin query?
This will work with Drupal 7 - I don't have other version to test it on but think it should work...

Because the version is stored in the text file CHANGELOG.txt we can write that to a table in the DB, read from the table, and then delete it again afterwards:

First run this: (make sure to change the path to your changelog file)

CREATE TABLE `drupal_version` (`data`  varchar(255) NULL);
LOAD DATA INFILE '/var/www/your_site/htdocs/CHANGELOG.txt' INTO TABLE drupal_version;
SELECT * FROM drupal_version WHERE data LIKE "%Drupal%" LIMIT 1;


This will return something like:

Drupal 7.26, 2014-01-15


And run this to delete the table we just made:

DROP TABLE drupal_version;


Whilst this is a long winded way of reading text from a text file it is strictly speaking getting the version using MySQL...

Second Option

As Topsitemakers suggested looking in the system table I had a look and found the version was hidden in there, but only against specific modules. I figured the field module would be in all version of drupal, however I very highly doubt that this query will actually work on any version other that 7 as it's so specific and a bit of a beast:

SELECT MID(info, LOCATE(':"', info, LOCATE('"version";', info)) + 2, MID(info, LOCATE('"version";', info) + 12, LOCATE(':"', info, LOCATE('"version";', info)) - LOCATE('"version";', info) - 12))
FROM system WHERE filename LIKE "%/field.module"


For me this query returns:

7.26