Assign query result to a variable and return variable

private int getuserid(String username){
        
            SqlConnection con = new SqlConnection(_conString);
            SqlCommand cmd = new SqlCommand();
            cmd.CommandType = CommandType.Text;

            cmd.CommandText = "SELECT USER_ID from tblUser where USERNAME ='" +username+"'";
            int locid = Convert.ToInt32(cmd.CommandText);

            return locid;
        }

Hi everyone, do you have an idea on how to assign value of user_id in a variable and return it. I tried but I am not sure its good.