問題描述

Warning: mysqli_query() expects at least 2 parameters, 1 given in D:phpstudy_proWWWallusers.php on line 31Warning: mysqli_num_rows() expects parameter 1 to be mysqli_result, null given in D:phpstudy_proWWWallusers.php on line 33

下面是代碼

//查詢數據表中的所有數據

$result=mysqli_query("SELECT * FROM users BY id DESC");

//獲取數據表的數據條數

$dataCount=mysqli_num_rows($result);

//echo $dataCount;

//打印輸出所有數據

問題解答

mysqli_query()接收兩個參數,第一個參數是MySQL 連接