Not sure why it’s escaping the % in your last example, because that works fine for me:
// lifted from my code:
var value="ee20e966289cd7";
connection.query('SELECT * from django_session where session_key like ?', '%' + value + '%', ...)
// Result:
[ { session_key: '713ee20e966289cd71b936084a1e613e', ... } ]
When I turn on debugging in the driver (pass debug:true as argument to mysql.createConnection), it doesn’t escape the percent sign:
{ command: 3,
sql: 'SELECT * from django_session where session_key like \'%ee20e966289cd7%\'' }
(it does escape the single quote, but that’s for display purposes only)
(using mysql@2.0.0-alpha8)