将ajax插入mysql“未定义变量”

Question

我无法插入到表中，因为查询具有未定义的变量startDate和endDate，我用ajax将其转移到php，但我不知道为什么它会在php查询中写入未定义的变量

<!-- language: lang-php -->

    //file insertDatenbank.php
    //PHP PART
    <?php

    $localhost  =   "localhost";
    $username   =   "root";
    $password   =   "";
    $db         =   "gpsauge_projektarbeit2";

    $link = mysqli_connect($localhost, $username, $password, $db);

    if(!$link){
        echo "Keine Verbindung";
    }

    if(!empty($_POST["startDatum"]) && !empty($_POST["endDatum"]))
        {
            $startDatum             =   mysqli_real_escape_string($link, $_POST["startDatum"]);
            $endDatum               =   mysqli_real_escape_string($link, $_POST["endDatum"]);
        } else{
            echo "Probleme bei Variablen Initialisierung";
        }

        $query = "insert into urlaubsantrag (start_datum, end_datum) values ('$startDatum', '$endDatum');";
        var_dump($query);

        $sql        = mysqli_query($link, $query);

    if($sql == true){
        echo "erfolgreich";
    } else{
        echo "probleme ende";
    }

<!-- language: lang-php -->

    //file beantragen.php
    <!--HTML-STARTDATUM---------------------------------------------------------->
            <div class="container">
            <div class="row">
                <h2>Startdatum</h2>
            </div>
            <div class="row">
                <div class='col-sm-6'>
                        <div class="form-group">
                            <div class='input-group date' id='datepicker'><!--id="startDatum" = ENDATE"-->
                                <input type='text' id="startDatum" class="form-control" />
                                <span class="input-group-addon">BLABLA
                                    <span class="glyphicon glyphicon-calendar"></span>
                                </span>
                            </div>
                        </div>
                    </form>
                </div>
            </div>
        </div>
      <!--HTML-ENDDATUM----------------------------------------------------------->
            <p id="data">Hier muss Data stehen</p>
            <div class="container">
            <div class="row">
                <h2>Enddatum</h2>
            </div>
            <div class="row">
                <div class='col-sm-6'>
                    <form>
                        <div class="form-group">
                            <div class='input-group date' id='datepicker2'> <!--id="endDatum" = ENDATE"-->
                                <input type='text' id="endDatum" class="form-control"/>
                                <span class="input-group-addon">BLABLA
                                    <span class="glyphicon glyphicon-calendar"></span>
                                </span>
                            </div>
                            <br><input id="button" type="button" value="Bestätigen">
                        </div>
                    </form>
                </div>
            </div>
        </div>
    <!--AJAX PART----------------------------------------------------------------->
     $(document).ready(function(){
        $('#button').click(function(){
            var startDatum  = $('#startDatum').val();
            var endDatum    = $('#endDatum').val();

            $.ajax({
                type: "post",
                url: "insertDatenbank.php",
                data: {
                    startDatum: startDatum,
                    endDatum: endDatum
                },
                success: function (data) {
                    $('#data').html(data);
                }
            });
        });
    });

  

错误消息：变量初始化问题注意：   未定义的变量：中的startDatum   /opt/lampp/htdocs/dashboard/USFACHINFORMATIKERIBBUNDIHK/PRAKTIKUM/TESTSUMGEBUNG/CALENDAR_VERSUCH_3/insertDatenbank.php   在第22行

     

注意：未定义变量：endDatum在   /opt/lampp/htdocs/dashboard/USFACHINFORMATIKERIBBUNDIHK/PRAKTIKUM/TESTSUMGEBUNG/CALENDAR_VERSUCH_3/insertDatenbank.php   在第22行string（67）“上插入urlaubsantrag（start_datum，   end_datum）值（''，''）;“ erfolgreich