php怎么提取mysql数据表的指定字段数据

Question

                $result = mysql_query("select * from brand order by yesterday_str");
                while($row = mysql_fetch_array($result))
                  {
                  echo "'".$row['yesterday_str']."'";
                  echo ",";
                  }

现在我通过上面的方法能把brand表里面的所有字段数据都提取出来

brand表里面有a,b,c,d,e,f,g这7个字段，
我怎么修改才能只提取abcfg这5个字段的数据呢？

Answer 1

 $result = mysql_query("select a,b,c,f,g from brand order by yesterday_str");
                while($row = mysql_fetch_array($result))
                  {
                  echo "'".$row['yesterday_str']."'";
                  echo ",";
                  }
                  
                  //这样就好了吧？？？？