AngularJS POST请求与同一PHP脚本之间发送和接收数据

I've looked extensively and still haven't found the answer to my question. I've gotten close, but I think that's as far as I can get on my own.

I have a database that has tables for different years, like so:

year_2016, year_2017, year_2018, etc...

I'm using PHP and MySQL to query these tables and using AngularJS to display them in HTML.

Here is my HTML:

<div id="main" ng-controller="MyController">
    <input type="text" placeholder="Search" autofocus ng-model="query" />
    <input type="text" placeholder="Year" ng-model="year" ng-blur="sendData()" />
    <div id="db-results" ng-show="query">
        <p><span>Searching for: "{{ query }}"</span></p>
        <p>{{ filtered.length }} results</p>
        <div class="container table">
            <div class="row" ng-repeat="item in items | limitTo : 100 | filter : query as filtered">
                <div class="col bg-info text-light rounded-left">{{ item.dir }}</div>
                <div class="col bg-warning text-dark">{{ item.index }}</div>
                <div class="col-lg-6 bg-light text-dark">{{ item.text }}</div>
            </div><!-- row -->
        </div><!-- table -->
    </div><!-- db-results -->
</div><!-- main -->

And my Angular:

var myControllers = angular.module('myControllers', []);

myControllers.controller('MyController',
    function MyController($scope, $http) {
        $scope.year = 2018;

        $scope.sendData = (function () {
            var data = $.param({
                year: $scope.year
            });
            var config = {
                headers: {
                    'Content-Type': 'application/x-www-form-urlencoded; charset=utf-8;'
                }
            };

            var postURL = 'mysql_conn.php';

            $http.post(postURL, data, config)
            .then(
                function(response){
                    console.log(data);
                    console.log('post_year=' + response.data.year);
                    $scope.items = response.data.records;
                }, 
                function(response){
                    console.log('failure ' + response);
            });

        })();
});

And finally, the PHP:

<?php

header("Access-Control-Allow-Origin: *");

$request = json_decode(file_get_contents('php://input', true));
$year = $request->year;
// $year = 2018;

$conn = new mysqli("SERVER", "USER", "PASSWORD", "DATABASE");

$result = $conn->query("SELECT * FROM year_" . $year . " LIMIT 100;");

$output = "";
while($rs = $result->fetch_array(MYSQLI_ASSOC)) {
    if ($output != "") {$output .= ",";}
    $output .= '{"dir":"' . $rs["dir_index"] . '",';
    $output .= '"index":"' . $rs["sub_index"] . '",';
    $output .= '"text":"' . $rs["text"] . '"}';
}

$output ='{"records":[' . $output . '], "year": ' . $year . '}';
$conn->close();

echo($output);

?>

I can set the $year variable in PHP statically and it queries everything from the table corresponding to that year, and then on my actual web page, I can type in a search and it will filter the records accordingly. That much works.

What I want to be able to, that I can't do already, is type in the year in the year input box and have the PHP re-query the appropriate table and display the results. In other words, I want the year input box to be responsive. PHP is not dynamic, so I thought Angular/AJAX might be able to help me out here.

In the Angular code, I am using http.post to send the value of $scope.year to PHP to then query the corresponding table. At least, that's what I'm trying to do. It's not working. In PHP, part of the output JSON is the $year variable that should be identical to the $scope.year model, but when I print it to the console in Angular, it returns undefined. I'm also using the same POST request to get the data that PHP queries from the database (this works).

I had also tried using separate GET and POST requests but this didn't work.

Thanks!