I'm trying to add a technicien in my servicedesk application but I have an error.

My error is the following : Unable to save technician : Login with same name already exists. Please provide different value for Login Name.

I have verify the Login Name and it doesn't exist !

When I run the following request : 

select a.first_name'First Name',al.name'Login Name',sd.status'Status',sd.userid'userid' from aaauser a left join aaalogin al on al.user_id=a.user_id left join sduser sd on sd.userid=a.user_id  where al.name='loginname';

I don't have results... 

PS : I have the same problem when I try to create a new requester...

Can you help me please ?

Thanks in advance