i had the same problem. information spread over 3 tables with 1:n relation. just specify in JOIN as table. look at my exmaple: $Self->{CustomerUser} = { Name => 'Database Backend', Module => 'Kernel::System::CustomerUser::DB', Params => { DSN => 'DBI:ODBC:EV_NEU', Table => 'Adresse LEFT OUTER JOIN Kunde ON Kunde.Adresse_ID = Adresse.ID LEFT OUTER JOIN Ansprechpartner ON Ansprechpartner.Adresse_id = Adresse.ID', }, # customer uniq id CustomerKey => 'Adresse_Matchcode', # customer # CustomerID => 'KtoNr', CustomerValid => 'IstFirma', CustomerUserListFields => ['Adresse.Firmenname_1','Adresse.Firmenname_2'], CustomerUserNameFields => ['Ansprechpartner.Nachname'], ReadOnly => 1, Map => [ [ 'UserCompanyname', 'Firmenname', 'Adresse.Firmenname_1', 1, 1, 'var' ], [ 'UserFirstname', 'Vorname', 'Ansprechpartner.Vorname', 1, 1, 'var' ], [ 'UserLastname', 'Nachname', 'Ansprechpartner.Nachname', 1, 1, 'var' ], [ 'UserLogin', 'Login', 'Adresse_Matchcode', 0, 1, 'var' ], [ 'UserPassword', 'Password', 'Adresse_Matchcode', 0, 1, 'var' ], [ 'UserEmail', 'Email', 'Ansprechpartner.E_mail', 1, 1, 'var' ], [ 'UserCustomerID', 'CustomerID', 'Ktonr', 0, 1, 'var' ], [ 'ValidID', 'Valid', 1, 0, 1, 'int' ], ], }; i hope this gives you a hint. best regards pcs