我怎样才能使该SQL查询正常工作？

Question

I am making a game for class and I decided to make a leaderboards page. As I have an admin area too I need to grab data from both tables in the page.

The two tables are user_settings and leaderboards . This is the code on my leaderboards.php page:

    <?php $records = array();

    if ($results = $db->query("SELECT * FROM user_settings UNION SELECT * FROM leaderboards")) {
        if ($results->num_rows) {
    while ($row = $results->fetch_object()) {
        $records[] = $row;
    }
    $results->free();
        }
    }

      ?>
    <?php foreach ($records as $data) { ?>

...the HTML etc...

<?php } ?>

What do I need to change in order to make this query work. Do I need to change the foreach loop? or...? I have only so far needed to grad data from one table so I'm not sure how to get this to work.

EDIT:

The user_settings table is for admin set config such as the site name etc. So far all I am doing is trying to do is select all from two tables without the page breaking, at the moment it is breaking. I have a feeling it is to do with the foreach loop and some of the code underneath the query. At the moment I do not want to grab any data from the database, I just want to select all successfully so the page doesn't break.

Answer 1

As @Kai Qing stated you are using UNION . As I don't know what your table structures are I cannot guarantee this is what you are after however I believe you are wanting to select all from two tables that do not share the same structure therefore you will want to do:

if ($results = $db->query("SELECT * FROM user_settings, leaderboards")) {

I hope this helps.