为什么这段代码会给我重复的结果？

This is probably really easy and I'm probably gonna kick myself up the arse after this, but I have the following code which displays either html or json of data from a table and returns it.

<?php
session_start();
$base = dirname(dirname(__FILE__));
include($base."/include/db.php");

global $conn;
$trees = [];
$treeBoxes = [];
if(isset($_SESSION['clientId'])) {
    $clientId = $_SESSION['clientId'];
    $query = $conn->prepare("SELECT * FROM ct_trees WHERE client_id=?");
    $query->bind_param('i', $clientId);
    $query->execute();
    $result = $query->get_result();
    if($result->num_rows > 0) {
        while($row = $result->fetch_assoc()) {
            $tree_id = $row['id'];
            $tree_name = $row['name'];
            $query = $conn->prepare("SELECT id FROM ct_connections WHERE tree_id=?");
            $query->bind_param('i', $tree_id);
            $query->execute();
            $result2 = $query->get_result();
            $connections = $result2->num_rows;
            array_push($treeBoxes, '<span class="checkbox abc-checkbox abc-checkbox-success">',
            '<input id="tree'.$tree_id.'" type="checkbox" rel="'.$tree_id.'">',
            '<label for="tree'.$tree_id.'">'.$tree_name.'</label>',
            '</span>');
            array_push($trees, ["id" => $tree_id, "name" => $tree_name, "connections" => $connections]);
            if(isset($_GET['json'])) {
                echo json_encode($trees);
            } else {
                echo join("", $treeBoxes);
            }
        }
    }
}
?>

Now let's say for example, we want the json result, I'm getting the following string:

[{"id":1,"name":"My Tree","connections":4360}][{"id":1,"name":"My Tree","connections":4360},{"id":4,"name":"Another Tree","connections":0}]

Now for some reason, it's giving me the first result in one array, and then the same result, but with the other rows, in a separate array.

Fixed it, I knew it'd be silly:

<?php
session_start();
$base = dirname(dirname(__FILE__));
include($base."/include/db.php");

global $conn;
$trees = [];
$treeBoxes = [];
if(isset($_SESSION['clientId'])) {
    $clientId = $_SESSION['clientId'];
    $query = $conn->prepare("SELECT * FROM ct_trees WHERE client_id=?");
    $query->bind_param('i', $clientId);
    $query->execute();
    $result = $query->get_result();
    if($result->num_rows > 0) {
        while($row = $result->fetch_assoc()) {
            $tree_id = $row['id'];
            $tree_name = $row['name'];
            $query = $conn->prepare("SELECT id FROM ct_connections WHERE tree_id=?");
            $query->bind_param('i', $tree_id);
            $query->execute();
            $result2 = $query->get_result();
            $connections = $result2->num_rows;
            array_push($treeBoxes, '<span class="checkbox abc-checkbox abc-checkbox-success">',
                '<input id="tree'.$tree_id.'" type="checkbox" rel="'.$tree_id.'">',
                '<label for="tree'.$tree_id.'">'.$tree_name.'</label>',
                '</span>');
            array_push($trees, ["id" => $tree_id, "name" => $tree_name, "connections" => $connections]);
        }
        //Moved echo outside of while loop.
        if(isset($_GET['json'])) {
            echo json_encode($trees);
        } else {
            echo join("", $treeBoxes);
        }
    }
}
?>