I have categories with very long names.
On upgrade from moodle 1.9 this causes error:

!!! Error writing to database !!!
!! Data too long for column 'name' at row 27
UPDATE mdl_question SET name = ? WHERE qtype = 'random' AND category = ? AND questiontext = ?
[array (
0 => 'Random ( VERY LONG STRING HERE IN RUSSIAN (two bytes per char in utf8) and sub-categories)',
1 => '7926'
2 => '1',
)] !!
!! Stack trace: * line 394 of /lib/dml/moodle_database.php: dml_write_exception thrown

• line 1056 of /lib/dml/mysqli_native_moodle_database.php: call to moodle_database->query_end()
• line 50 of /question/type/multichoice/db/upgrade.php: call to mysqli_native_moodle_database->set_field_select()
• line 373 of /lib/upgradelib.php: call to xmldb_qtype_multichoice_upgrade()
• line 1421 of /lib/upgradelib.php: call to upgrade_plugins()
• line 146 of /admin/cli/upgrade.php: call to upgrade_noncore()

problem is in /question/type/multichoice/db/upgrade.php:
where str length of $randomqname is not limited.

$randomqname = $QTYPES[RANDOM]->question_name($cat, false);
$DB->set_field_select('question', 'name', $randomqname, $where, array($cat->id, '0'));

better is to limit it into
/question/type/random/questiontype.php :

function question_name($category, $includesubcategories) should be something like :

function question_name($category, $includesubcategories) {

+$max = 50;

+$str = $category->name;

+if (mb_strlen($str,'utf-8') > $max) {$str = mb_substr($str,0,$max-3,'utf-8').'...';}

if ($includesubcategories)

else

return get_string($string, 'qtype_random', $category>name);
+return get_string($string, 'qtype_random', $str);
}