mysqli_num_rows无论如何返回1

Question

当我在phpMyAdmin中进行SQL搜索(用变量替换实际值)时,它会返回正确的行号,但是当使用PHP返回此值时,无论如何都会返回1.提前致谢.

function user_exists($username) {
    $link = mysqli_connect('localhost','root','','test');
    $username = sanitize($username);
    $query = mysqli_query($link, "SELECT COUNT(`user_id`) FROM `new_base` WHERE `username`='$username'");
    $row_cnt = mysqli_num_rows($query);
    echo $row_cnt;
    mysqli_free_result($query);
    mysqli_close($link);
}

Answer 1

使用时COUNT(*),即使计数为零,也始终返回一行.

你要么:

1. 想要删除count(*)然后使用mysqli_num_rows() 或
2. 得到结果 count(*)

.

$row = mysqli_fetch_assoc($query);
echo $row['COUNT(`user_id`)'];