php 链接mysql 超时处理

<?php


$conn = mysql_connect($dbhost, $dbuser, $dbpw) or die('Could not connect: ' . mysql_error());
mysql_select_db($dbname) or die('Could not select database');
mysql_query("set names 'utf8'"); 


echo "other work of waste time \n";
sleep("20"); // 其他费时工作



 //检查数据库是否失去连接 如果数据库 $conn 超时失效则重新联接
$checkDbLink = mysql_query("set names 'utf8'",$conn);
if(!$checkDbLink){ 
	getDbLink($conn);
}

$sqlData = "select id,dateline,page_num,top_channel_id from cms_article where id > 5 limit 1 ";
$rs = mysql_query($sqlData,$conn);
$line = mysql_fetch_array($rs);
echo $line['id']."\n";


function getDbLink(&$conn){
	global $dbhost, $dbuser, $dbpw,$dbname;
	mysql_close($conn); // 失去数据库连接,如果要重建连接必须要 关闭原来的资源然后再重新建立
        $conn = '';
	$conn = mysql_connect($dbhost, $dbuser, $dbpw) or die('Could not connect: ' . mysql_error());
	mysql_select_db($dbname,$conn) or die("Could not select database  ".mysql_error());
	
}


mysql_close($conn);




?>

处理成函数：

// 检查数据库是否失去连接，如果失去连接则重新建立链接
function checkDbLink($dbhost, $dbuser, $dbpw,$dbname,&$conn){
	$rsCheck = mysql_query("set names 'utf8'",$conn);
	if(!$rsCheck){
		mysql_close($conn);  $conn = '';
		$conn = mysql_connect($dbhost, $dbuser, $dbpw) or die('Could not connect: ' . mysql_error());
		mysql_select_db($dbname,$conn) or die("Could not select database at common.php ".mysql_error());
		mysql_query("set names 'utf8'",$conn); 	
	}
}

        private function dbQuery($sql) {
                try{
                        $result = mysql_query($sql, $this->conn);
                }catch (Exception $e) {
                         $mysqlErrno = mysql_errno();
                         if(in_array($mysqlErrno, array(2006,2013))) {
                                $this->getConn();
                                $result = $this->dbQuery($sql);
                         }
                }
                
                return $result;
        }

或者最简单在脚本最前面加一条语句

mysql_query("set wait_timeout = 50");