var dpb: String;
...
    dpb := fb_dpb_version1+
           fb_dpb_user_name+Char(Length(AdminUser))+AdminUser+
           fb_dpb_password+Char(Length(DecryptedPassword))+DecryptedPassword;
    if Length(Charset) > 0 then
      dpb := dpb+fb_dpb_lc_ctype+Char(Length(Charset))+Charset;
    if Length(AdminRole) > 0 then
     begin
      dpb := dpb+
             fb_dpb_sql_dialect+#1+#0+ // In case of quoted role
             fb_dpb_sql_role_name+Char(Length(AdminRole))+AdminRole;
     end;

    Call(fb_attach_database(status_vector, 0, PChar(ConnectionString),
                            Db,Length(dpb), PChar(dpb)));

procedure TFBConfiguration.LoadDatabases;
var
  QryCfg : TFBCursor;
begin
  inherited;
  StartTransaction;
  try
   RunFBSQL(DbCfg, TransCfg, QryCfg,
            'SELECT DBNO,DBPATH,DBNAME,ADMINUSER,ADMINPASSWORD,COMMENTS,'+
            'PRIORITY,TIMEFIELDNAME,CHARSET,DBTYPE,USERROLE,DIALECT,'+
            'DIALUSERNAME,DIALPASSWORD,RASNAME,KEEPCONNECTION,MOREPARAMS'+
            ' FROM REPL$DATABASES',
            17, Dialect);
   While not QryCfg.Eof do
    begin
     AddDbToCache(GetIntegerValue(DbCfg, TransCfg, QryCfg, 0),
                  GetStringValue(DbCfg, TransCfg, QryCfg, 1),
                  GetStringValue(DbCfg, TransCfg, QryCfg, 2),
                  GetStringValue(DbCfg, TransCfg, QryCfg, 3),
                  GetStringValue(DbCfg, TransCfg, QryCfg, 4),
                  GetStringValue(DbCfg, TransCfg, QryCfg, 5),
                  GetIntegerValue(DbCfg, TransCfg, QryCfg, 6),
                  GetStringValue(DbCfg, TransCfg, QryCfg, 7),
                  GetStringValue(DbCfg, TransCfg, QryCfg, 8),
                  GetIntegerValue(DbCfg, TransCfg, QryCfg, 9),
                  GetStringValue(DbCfg, TransCfg, QryCfg, 10),
                  GetIntegerValue(DbCfg, TransCfg, QryCfg, 11),
                  GetStringValue(DbCfg, TransCfg, QryCfg, 12),
                  GetStringValue(DbCfg, TransCfg, QryCfg, 13),
                  GetStringValue(DbCfg, TransCfg, QryCfg, 14),
                  GetIntegerValue(DbCfg, TransCfg, QryCfg, 15),
                  GetStringValue(DbCfg, TransCfg, QryCfg, 16));
     Next(QryCfg);
    end;
   FreeCursor(QryCfg);
   CommitTransaction;
  except
   RollbackTransaction;
   raise;
  end;
end;