按提交按钮后的空白页，所有字段均已填写

Question

如标题所示，我有一个供用户创建项目的页面和另一个页面将其添加到我的数据库中。 但是，当我在表单字段为空的情况下按提交时，它发布到的页面不是空白的。 但是当我在填写字段的情况下提交时，它只是显示一个没有任何错误的空白页面，我查看了两页代码但似乎找不到任何错误。 也许这里有人可以帮助我？ 谢谢。

//提交数据的页面上的代码。

if ($_POST['projectTitle'] != "" && $_POST['projectStatus'] != "" && $_POST['projectDesc'] != "" && $_POST['projectDeliv'] != "" && $_POST['year'] != "" && $_POST['month'] != "" && $_POST['day'] != "" && $_POST['projectSS'] != "") {

        $host = "localhost";
        $user = "root";
        $pass = "";
        $db = "fyp1";

        $pt = $_POST['projectTitle'];
        $ps = $_POST['projectStatus'];
        $pdes = $_POST['projectDesc'];
        $pdel = $_POST['projectDeliv'];
        $date = $_POST['year'] . "-" . $_POST['month'] . "-" . $_POST['day'];
        $pss = $_POST['projectSS'];
        date_default_timezone_set('UTC+8');
        $cDate = date('Y-m-d');
        $uid = $_SESSION['id'];

        $link = mysqli_connect($host, $user, $pass, $db) or die(mysqli_error());
        $query = "SELECT * FROM project WHERE project_title = $pt AND project_description = $pdes AND project_deliverables = $pdel AND project_skillset = $pss";
        $dub = mysqli_query($link, $query) or die(mysqli_connect_error($link));

        if (mysqli_num_rows($dub) == 0) {

            $insertQ = "INSERT INTO project(project_title,project_description,project_deliverables,project_start,project_end,project_skillset,project_status)
                VALUES ('$pt','$pdes','$pdeliv','$cDate','$date','$pss',$ps)";
            mysqli_query($link, $insertQ) or die(mysqli_connect_error($link));

            $getPID = "SELECT * FROM project WHERE project_title = $pt AND project_description = $pdes AND project_deliverables = $pdel AND project_start = $cDate AND projecct_end = $date AND project_skillset = $pss";
            $pid = mysqli_query($link, $getPID) or die(mysqli_connect_error($link));
            if (mysqli_num_rows($pid) == 1) {
                while ($row = mysqli_fetch_array($pid)) {
                    $proid = $row['project_id'];
                    $insertF = "INSERT INTO user_has_project(user_id,project_id) VALUES ('" . $uid . "','" . $proid . "')";
                    mysqli_query($link,$insertF) or die(mysqli_connect_error($link));
                    $message = "<p>Project Successfully Added!</p>";
                    $message .= "<a href='index.php'>Back</a>";
                    $a = true;
                }
            } else {
                $message = "<p>Project Failed To Be Added!</p>";
                $message .= "<a href='createProject.php'>Back</a>";
                $a = false;
            }
        } else {
            $message = "<p>Duplicate Project Found!</p>";
            $message .= "<a href='createProject.php'>Back</a>";
            $a = false;
        }
    } else {
        $message = "<p>Please Fill Up All Fields When Creating A Project!</p>";
        $message .= "<a href='createProject.php'>Back</a>";
        $a = false;
    }

// 带有表单的页面上的代码

    <div id="content">
        <?php if ($a == false) {
        ?>
                <h2 id="registerFont">Create Project</h2>
                <form name="createProject" method="post" action="doCreateProject.php" onSubmit="return validateForm(this);">
                    <fieldset>
                        <table>
                            <tr>
                                <th colspan="4"><h2>New Project</h2></th>
                            </tr>
                            <tr>
                                <th colspan="4"><hr /></th>
                            </tr>
                            <tr>
                                <td><label for="projectTitle">Project Title:</label></td><td><input name="projectTitle" type="text" /></td>
                                <td><label for="projectStatus">Project Status:</label></td>
                                <td><select name="projectStatus">
                                <?php while ($row = mysqli_fetch_array($result1)) {
                                ?>
                                    <option value="<?php echo $row['status_id']; ?>" ><?php echo $row['status_type']; ?></option>
                                <?php } ?>
                            </select></td>
                    </tr>
                    <tr>
                        <td><label for="projectDesc">Project Description:</label></td><th colspan="3"><textarea name="projectDesc" rows="5" cols="40" ></textarea></th>
                    </tr>
                    <tr>
                        <td><label for="projectDeliv">Project Deliverables:</label></td><th colspan="3"><textarea name="projectDeliv" rows="5" cols="40" ></textarea></th>
                    </tr>
                    <tr>
                        <td>Start Date:</td><td><?php echo $date; ?></td>
                    </tr>
                    <tr>
                        <td>End Date : </td>
                        <th colspan="3" align="left">
                            <select name="year">
                                <option>---Year---</option>
                                <?php for ($i = $cYear; $i < ($cYear + 100); $i++) {
                                ?>
                                    <option value="<?php echo $i; ?>"><?php echo $i; ?></option>
                                <?php } ?>
                            </select>
                            <select name="month">
                                <option>---Month---</option>
                                <?php while ($rows = mysqli_fetch_array($result)) {
                                ?>
                                    <option value="<?php echo $rows['month_id']; ?>"><?php echo $rows['month']; ?></option>
                                <?php } ?>
                            </select>
                            <select name="day">
                                <option>---Day---</option>
                                <?php for ($i = 1; $i < 32; $i++) {
                                ?>
                                    <option value="<?php echo $i ?>"><?php echo $i ?></option>
                                <?php } ?>
                            </select>
                        </th>
                    </tr>
                    <tr>
                        <td><label for="projectSS">Project Skill Set:</label></td><td><input name="projectSS" type="text"/></td><th colspan="2"><small>(Please Separate By Comma)</small></th>
                    </tr>
                </table>
            </fieldset>
            <br />
            <input name="submit" type="submit" value="Create Project" />
        </form>
        <?php
                            } else {
                                echo $message;
                            }
        ?>
                        </div>

Answer 1

我设法解决了这个问题。 查询数据库时，在我的 SELECT 语句中，我忘记添加“”的变量。 例如 SELECT * FROM project WHERE project_title = '$variable';

无论如何。 感谢那些帮助过的人。 对此，我真的非常感激。