PHP访问MySQL查询超时处理（转载）

//自己定义读写超时常量
if (!defined('MYSQL_OPT_READ_TIMEOUT')) {
        define('MYSQL_OPT_READ_TIMEOUT',  11);
}
if (!defined('MYSQL_OPT_WRITE_TIMEOUT')) {
        define('MYSQL_OPT_WRITE_TIMEOUT', 12);
}

//设置超时
$mysqli = mysqli_init();
$mysqli->options(MYSQL_OPT_READ_TIMEOUT, 3);
$mysqli->options(MYSQL_OPT_WRITE_TIMEOUT, 1);

//连接数据库
$mysqli->real_connect("localhost", "root", "123456", "discuz");
if (mysqli_connect_errno()) {
   printf("Connect failed: %s\n", mysqli_connect_error());
   exit();
}

//执行查询 sleep 1秒不超时
printf("Host information: %s\n", $mysqli->host_info);
if (!($res=$mysqli->query('select sleep(1)'))) {
    echo "query1 error: ". $mysqli->error ."\n";
} else {
    echo "Query1: query success\n";
}

//执行查询 sleep 9秒会超时
if (!($res=$mysqli->query('select sleep(9)'))) {
    echo "query2 error: ". $mysqli->error ."\n";
} else {
    echo "Query2: query success\n";
}

$mysqli->close();
echo "close mysql connection\n";

作者：http://blog.csdn.net/heiyeshuwu/archive/2010/09/08/5869813.aspx