仅在php,mysql 中显示前50个字符

参见英文答案 > How do you pull first 100 characters of a string in PHP6个
我在数据库表,标题和描述中有两个字段.我在循环中显示php中的数据.

我的代码：

$sql = "select * from sightseeing";
    $i = 1;
    $res = mysql_query($sql,$conn); 
    if( mysql_num_rows($res) > 0) {
        while($row = mysql_fetch_array($res))
       {

        echo "

 $sql = "select * from sightseeing";
$i = 1;
$res = mysql_query($sql,$conn); 
if( mysql_num_rows($res) > 0) {
    while($row = mysql_fetch_array($res))
{

echo "