mysql 函数left

?php
    $conn = mysql_connect('localhost','root','123456');
    mysql_query('set names gbk');
    mysql_select_db('test');
    $sql = "select left(address,5) as address from user";
   
    $rs = mysql_query($sql, $conn);
    while($row = mysql_fetch_assoc($rs))
    {
        echo $row[address]."
";
    }
?>
得到指定长度的数据,MYSQL本身就有这个函数,left 与right 试过也不会出现 '?' 等情况
这样也很方便.