我的.show（）不起作用，但.hide有效

Question

在getRequest（）函数中还有一个.show，它在那里工作，但在if else语句的其余部分，.show（）不起作用。

function bySubject(subject){
    if (subject != "All" && subject != "user-2") {
        getRequest(subject);
    }
    else if( subject == "user-2" ){
        $("tr.req-row").hide();
        $("tr.user-2").show();
    }
    else{
        $("tr.req-row").show();
    }
}

我该如何解决这个问题？我不认为语法有问题，是吗？

已编辑：已添加HTML代码

//dropdown where i get the value of subject
if ($subject_numrows > 0) {
                    $subjects = $function->select_result( $link, $subject_query );
            ?>
                    <table>
                        <tr>
                            <td><label for="select-subject" >View by: </label></td>
                            <td>
                                <select name="select-subject" id="select-subject" class="form-control" onchange="bySubject(this.value)">
                                        <option value="All">All</option>
                                        <?php
                                            foreach ( $subjects as $value ) { 
                                        ?>
                                                <option value="<?php echo $value['SubjectName']; ?>"><?php echo $value['SubjectName']; ?></option>
                                        <?php     
                                            }
                                        ?>
                                        <option value="user-3">Other Dept./Org.</option>
                                </select>
                            </td>
                        </tr>
                    </table>
            <?php
                }
            ?>

//table to display the result.
<table class="table table-striped table-bordered responsive">
                <tr>
                    <th class="req-th"><center>Today's Requests<center></th>
                </tr>
                <tbody>
                <?php 
                        if ( $req_numrows > 0 ) {

                        $request_details = $function->select_result( $link, $request_query );

                            foreach ($request_details as $value) {
                                $req_id = $value['Request_ID'];
                                $userid = $value['User_ID'];
                                $status = $value['Request_Status'];
                                $sqldate = $value['Date_Needed'];
                                $date = strtotime($sqldate);

                                $query = "SELECT * FROM usertbl WHERE User_ID='$userid'";
                                $result = mysqli_query($link, $query);
                                $user_row = mysqli_fetch_array($result);
                                $usertype = $user_row['UserType'];
                                /*if ( $status == "PENDING" || $status == "NOTED" || $status == "CHECKED") {
                                    $status_class = "label-warning label label-default";
                                }
                                if ( $status == "APPROVED" ) {
                                  $status_class = "label-success label label-default";
                                }*/
                                if (date("F j, Y", $date) == date("F j, Y")) {
                                    echo "<tr class='req-row " . $status . " " . $usertype . "' id='" . $req_id . "'><td><table class='table'>";


                                    echo "<tr><td class='center name' style='border: 0 none;padding-top: 0px; padding-bottom: 0px;'>
                                              <label>ID No:</label>&nbsp&nbsp" . $value['User_ID'] . "
                                            </td></tr>";
                                    echo "<tr><td class='center name' style='border: 0 none;padding-top: 0px; padding-bottom: 0px;'>
                                              <label>Name:</label>&nbsp&nbsp" . $user_row['UserName'] . "
                                            </td></tr>";

                                    if ( $usertype == "user-2") {
                                        echo "<tr>";
                                        echo "<td class='center' style='border: 0 none;padding-top: 0px; padding-bottom: 0px; width: 500px'><label>Subject:</label>&nbsp&nbsp" . $value['Subject'] . "</td>";

                                        $profid = $value['Prof_ID'];
                                        $query = "SELECT * FROM usertbl WHERE User_ID='$profid'";
                                        $result = mysqli_query($link, $query);
                                        $prof_row = mysqli_fetch_array($result);
                                        echo "<td class='center' style='border: 0 none;padding-top: 0px; padding-bottom: 0px;'><label>Professor:</label>&nbsp&nbsp" . $prof_row['UserName'] . "</td>";
                                        echo "</tr>";
                                    }
                                    else{
                                        echo "<tr>";
                                        echo "<td class='center' style='border: 0 none;padding-top: 0px; padding-bottom: 0px;'><label>Purpose:</label>&nbsp&nbsp" . $value['Purpose'] . "</td>";
                                        echo "</tr>";
                                    }

                                        echo "<tr><td class='center' style='border: 0 none;padding-top: 0px; padding-bottom: 0px;'><label>Date Needed:</label>&nbsp&nbsp" . date("F j, Y", $date) . "</td>";
                                        echo "<td class='center' style='border: 0 none;padding-top: 0px; padding-bottom: 0px;'><label>Time Needed:</label>&nbsp&nbsp" . date("g:i a", strtotime($value['fromTime_Needed'])) . " to " . date("g:i a", strtotime($value['toTime_Needed'])) . "</td></tr>";
                                        echo "<tr><td colspan='2'>";
                                                echo "<button class='btn btn-danger viewbtn pull-right' href='' id=" . $value['Request_ID'] . "><i class='glyphicon glyphicon-ok icon-white'></i>
                                                      Release Equipments</button>";
                                            echo "</td></tr>";
                                        echo "</table></td</tr>";
                                }
                          }
                      }
                      else{
                          echo "<tr><td colspan='6'><center>No Request to display.</center></td></tr>";
                      }
                ?>
                </tbody>
            </table>

Answer 1

在将类名添加到tr时，您将放置空格。