我不能让它工作，我真的不知道如何调试它。在URL中，我要添加以下内容：？候选资格=41（&P）；selectCandidate=selectCandidate

global $wpdb;


    if(isset($_POST[\'selectCandidate\']))
    {
        global $wpdb;
        $selected_candidate = $_POST[\'candidat\'];  // Storing Selected Value In Variable
          $wpdb->query( $wpdb->prepare("UPDATE pp_candidates 
            SET candidate_approved = 1  WHERE candidate_ID = \'".$selected_candidate."\' "));
          $wpdb->show_errors();

    }

    if (!isset($_POST[\'candidatebutton\'])) 
        {echo \'<div class="projectcandidatelist"></div>\';
        }
    else
    {
    echo \'<div class="projectcandidatelist"><form action="" id="candidat_list">\';

    $project_candidat = $wpdb->get_results("SELECT *  FROM pp_candidates WHERE project_ID =\'".$_POST[\'candidatebutton\']."\' ");

    foreach($project_candidat as $candidat)
        {
        echo    \'<p><input type="radio" name="candidat" value="\'.$candidat->candidate_ID.\'" >
        <a href="\'.$candidat->candidate_url.\'">\'.$candidat->candidate_displayname.\'</a></p>\';
        }
        echo \'<input type="submit" value="selectCandidate" name="selectCandidate">\';

        echo \'</form></div>\';   
    }