StringBuilder的Append()方法会比+=效率高

  StringBuilder strSql = new StringBuilder();
            strSql.Append("select top 1 id from " + databaseprefix + "channel");
            strSql.Append(" where name=@name ");

StringBuilder的Append()方法会比+=效率高,StringBuilder比StringBuffer效率略高

+=，占资源的空间和时间