当mysqli_query返回正确的值时，mysqli_num_rows总是返回0

Question

我似乎对mysqli_num_rows函数有点了解。

我的mysql_query运行正常，返回它应该的内容，但是一旦我尝试计算返回的行数，num_rows就会一直返回0.

<?php
    if ($_SERVER["REQUEST_METHOD"] == "POST") {
    $connect = mysqli_connect( 'localhost', 'root', 'root', 'accounts');

    //check if two passwords are equal to each other
        if ($_POST['pass'] == $_POST['confirm_pass']) {

    //define email variable with submitted values from $_POST
        $email = $mysqli->real_escape_string($_POST['email']);

    //md5 hash 
        $pass = md5($_POST['pass']);

    //unique user test
        $query = mysqli_query($connect ,'SELECT * FROM users WHERE email="$_email"', MYSQLI_STORE_RESULT);
        $numrows = mysqli_num_rows($query);
        print_r ($numrows) ; die();

        }
    }
?>

非常感谢帮助我，这个功能我