Deprecated: mysql_connect(): The mysql extension is deprecated的解决方法

function connectit () {
global $CFG;
mysql_connect($CFG['db_host'], $CFG['db_user'], $CFG['db_pass']) or die(mysql_error());
mysql_select_db($CFG['db_name']);
}

PDO:
$dbh = new PDO('mysql:host=localhost;dbname=test', $user, $pass);

MYSQLI:
$link = mysqli_connect(
'localhost',  /* The host to connect to 连接MySQL地址 */
'user',      /* The user to connect as 连接MySQL用户名 */
'password',  /* The password to use 连接MySQL密码 */
'world');    /* The default database to query 连接数据库名称*/

if (!$link) {
printf("Can't connect to MySQL Server. Errorcode: %s ", mysqli_connect_error());
exit;
}