解决mysql FIND_IN_SET 查询不到数据

$con = mysql_connect("localhost","root","root");

//$dbname = "weixin";

function selectMsg($str)
{
    $rows = array();
    $msgArr = array();
    $like = array();
    $arr = array();

    $sql = "SELECT * FROM weixin.weixin_msg WHERE FIND_IN_SET('".$str."',Title)";
    $result = mysql_query($sql); 
    while($rows = mysql_fetch_array($result, MYSQL_ASSOC))
    {
        $msgArr[] = $rows;
    }
    if (!empty($msgArr)) {
        
        return $msgArr;

    }else{

        $sqlstr = "SELECT * FROM weixin.weixin_msg WHERE Title LIKE '%".$str."%' order by id desc";

        $like = mysql_query($sqlstr);

        while($arr = mysql_fetch_array($like, MYSQL_ASSOC))
        {
          $msgArr[] = $arr;
        }
            return $msgArr;
    }
        
}


function cityName($keyword)
{

    $sql = "SELECT * FROM weixin.weixin_cityname WHERE FIND_IN_SET('".$keyword."',CityNameCn)";
    $result = mysql_fetch_array(mysql_query($sql), MYSQL_ASSOC);
    print_r($result);

}

cityName("北京");

$res= selectMsg("123");
echo "<pre>";
print_r($res);

header("Content-Type: text/html;charset=utf-8");
//连接数据库
$con = mysql_connect("localhost","root","root");

mysql_query("set character set 'utf8'");//读库  
mysql_query("set names 'utf8'");//写库