code: func GenSQLServer(u *URL) (string, error) {
  	host, port, dbname := hostname(u.Host), hostport(u.Host), strings.TrimPrefix(u.Path, "/")
  
  	// add instance name to host if present
  	if i := strings.Index(dbname, "/"); i != -1 {
  		host = host + `\` + dbname[:i]
  		dbname = dbname[i+1:]
  	}
  
  	q := u.Query()
  	q.Set("Server", host)
  	q.Set("Port", port)
  	q.Set("Database", dbname)
  
  	// add user/pass
  	if u.User != nil {
  		q.Set("User ID", u.User.Username())
  		pass, _ := u.User.Password()
  		q.Set("Password", pass)
  	}
  
  	// save host, port, dbname
  	if u.hostPortDB == nil {
  		u.hostPortDB = []string{host, port, dbname}
  	}
  
  	return genOptionsODBC(q, true), nil
  }
docs: // GenSQLServer generates a mssql DSN from the passed URL.