問(wèn)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(shù)據(jù)表中的所有數(shù)據(jù)

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

//獲取數(shù)據(jù)表的數(shù)據(jù)條數(shù)

$dataCount=mysqli_num_rows($result);

//echo $dataCount;

//打印輸出所有數(shù)據(jù)

問(wèn)題解答

mysqli_query()接收兩個(gè)參數(shù),第一個(gè)參數(shù)是MySQL 連接