我的内爆问题是什么

始终通过打印值来调试代码，并检查其是否为所需的输出

有趣的是，你的check_list的post值是

$_POST['check_list'] = ['Jurufoto','Hiburan'];

所以根据你的代码像那样内爆之后

$check = implode("','", $_POST['check_list']);
$finalCheck = "'".$check."'";

你的$finalCheck字符串将是这样的"Jurufoto"，"Hiburan"

当你把它和这个这样的查询连接起来时

AND vendor.type IN ('%". $finalCheck ." %')" );

它变得像这个

 AND vendor.type IN ('%'Jurufoto','Hiburan' %')" );

哪个sql语句是错误的，你必须像这样修改

 AND vendor.type IN (". $finalCheck .")" );

或者，如果你想检查类似，那么你必须看到这个线程

MySQL IN与LIKE

确保在获取数据之前打印$sql，并将其与您想要的输出匹配

现在你的代码将像这个

<form method="post">
    <div class="form-group">
        <h3><label for="usr">Carian bajet anda:</label></h3>
        <div class="col-md-12">
            <div class=" col-md-4"></div>
            <div class=" col-md-4">
                <input name="bajet" type="text" class="form-control" id="usr">
            </div>
        </div>
        <div class=" col-md-4"></div>
    </div>
    <br>
    <h3><label for="sel1">Pilih negeri pilihan anda:</label></h3>
    <div class="col-md-12">
        <div class=" col-md-4"></div>
        <div class=" col-md-4">
            <select class="form-control" name="sel">
                <option>Kuala Lumpur</option>
                <option>Negeri Sembilan</option>
                <option>Pahang</option>
                <option>Perak</option>
                <option>Terengganu</option>
                <option>Selangor</option>
            </select>
        </div>
        <div class=" col-md-4"></div>
    </div>
    <br>

    <br>
    <h5><label for="check">Senarai Pra-perkahwinan:</label></h5>
    <center>
        <div class="checkbox">
            <label class="checkbox-inline"> <input type="checkbox" name="check_list[]"
                                                   value="Jurufoto"><label>Jurufoto</label></label>
            <label class="checkbox-inline"> <input type="checkbox" name="check_list[]"
                                                   value="Butik"><label>Butik</label></label>
            <label class="checkbox-inline"> <input type="checkbox" name="check_list[]"
                                                   value="Hiburan"><label>Hiburan</label></label>
            <label class="checkbox-inline"> <input type="checkbox" name="check_list[]" value="Kad Kahwin"><label>Kad
                    Kahwin</label></label>
            <label class="checkbox-inline"> <input type="checkbox" name="check_list[]"
                                                   value="Katering"><label>Katering</label></label>
            <br>
        </div>
    </center>
    <div class="col-md-4"></div>
    <div class="col-md-4">
        <button class="btn btn-success btn-sm" name="search">Search&nbsp;<span
                class="glyphicon glyphicon-search"></span></button>
        <br><br>
    </div>
    <div class="col-md-4"></div>
</form>
<table class="table table-bordered">
    <thead>
    <tr>
        <th>Jenis</th>
        <th>Vendor</th>
        <th>Negeri</th>
        <th>No.</th>
        <th>Pakej</th>
        <th>Harga</th>
        <th></th>
    </tr>
    </thead>
    <tbody>
    <?php
    if (isset($_POST['search'])) {
        $check = array();
        $budget = $_POST['bajet'];
        $select = $_POST['sel'];
        $check = implode("','", $_POST['check_list']);
        $finalCheck = "'" . $check . "'";
        $check = array();
        mysql_select_db($database_conn, $conn);
        $sql = mysql_query(" SELECT *
                 FROM vendor
                    RIGHT JOIN item
                      ON vendor.v_id=item.v_id
                        WHERE item.harga <= '%" . $budget . "%'
                          AND vendor.state = '%" . $select . "%'
                            AND vendor.type IN (" . $finalCheck . ")");
        while ($row = mysql_fetch_array($sql)) {
            ?>
            <tr>
                <td><?php echo $row['type'] ?></td>
                <td><?php echo $row['companyName'] ?></td>
                <td><?php echo $row['state'] ?></td>
                <td><?php echo $row['contact'] ?></td>
                <td><?php echo $row['harga'] ?></td>
                <td><?php echo $row['pakej'] ?></td>
                <td><a href="index.php?v_id=<?php echo $row['v_id'] ?>">View Package</a></td>

            </tr>
        <?php }
    }
    ?>
    </tbody>
</table>

不要使用mysql连接，因为mysql_*函数从5.5.0开始就被弃用了。使用mysqli或PDO进行数据库连接。

像这样使用

$check = implode(",", $_POST['check_list']);

由于您在创建$finalCheck时已经添加了单引号，因此无需在子句中再次添加单引号。

$sql = mysql_query(" SELECT * 
             FROM vendor 
                RIGHT JOIN item 
                  ON vendor.v_id=item.v_id
                    WHERE item.harga <= '%". $budget . "%' 
                      AND vendor.state = '%". $select ."%'
                        AND vendor.type IN (%". $finalCheck ." %)" );