php - 选择并减少 mysql 查询的字段值

Question

我对 mysql_query 有疑问 我试图找到在线的成员，成员表中有一个字段“在线”总是随时间服务器更新。这是查询。

$ now = time ();
$ olline = mysql_num_rows (mysql_query ("select * from members where gender = 'Man' and (online - '$ now')> 10"));

在phpmyadmin中有7个成员按照上面的查询。 tp 我得到的值为 0。我的代码有什么问题。谢谢你的回答，抱歉英语不好

Answer 1

这些天你应该尝试并始终使用 Mysqli，因为不久 Mysql 将完全消失。您的代码的 Mysqli 示例:

 $mysqli = new mysqli("localhost", "my_user", "my_password", "world");

/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}
$now = time(); // The time now for query calc
$gender = "Man"; // Gender for query

$stmt = $mysqli->stmt_init(); //Initialise statement
$stmt->prepare("SELECT * FROM members WHERE gender = ? AND (online - ?)> 10"); //Prepare the query
$stmt->bind_param('ss', $gender, $now); //Assign the query parameters
$stmt->execute(); // Execute the query
$stmt->store_result(); // store result of prepared statement
echo $stmt->num_rows;
$stmt->free_result(); //free up the $stmt var