<?php

require '../dao/TagConcernDao.php';
$tagName = $_REQUEST['tagName'];
$userId = $_REQUEST['userId'];
$tagConcernDao = new TagConcernDao();
if ($tagConcernDao->setTagConcern($tagName, $userId) > 0) {
    echo json_encode(array('mesg' => 'success', 'result' => true));
} else {
    echo json_encode(array('mesg' => 'fail', 'result' => false));
}
<?php

require '../dao/TagConcernDao.php';
$tagName = $_REQUEST['tagName'];
$userId = $_REQUEST['userId'];
$tagConcernDao = new TagConcernDao();
if ($tagConcernDao->cancelTagConcern($tagName, $userId) > 0) {
    echo json_encode(array('mesg' => 'success', 'result' => true));
} else {
    echo json_encode(array('mesg' => 'fail', 'result' => false));
}
<?php

require '../dao/TagConcernDao.php';
$userId = $_REQUEST['userId'];
$tagConcernDao = new TagConcernDao();
echo $tagConcernDao->getTagConcernList($userId);