php - 尝试限制表单提交的数量

Question

因此，本质上，登录用户应该只能提交一次他们的首选项，然后从表中进行编辑。

if(isset($_POST['userPrefSave'])){
    $studetnPrefId=$_POST['studentPrefId'];
    $studentId=$_POST['studentId'];

    $result= limitUserPref($studentPrefId,$studentId);
    //print_r($result);
    if(isset($result)< 1){
    $studentPrefId=$_POST['studentPrefId'];
    $studentId=$_POST['studentId'];
    $english=$_POST['english'];
    $math=$_POST['math'];
    $science=$_POST['science'];
    $history=$_POST['history'];
    $oralComm=$_POST['oralComm'];
    $pe=$_POST['pe'];
    $health=$_POST['health'];
    $art=$_POST['art'];
    $electives=$_POST['electives'];
    setUserPref($studentPrefId, $studentId, $english, $math, $science, $history, $oralComm, $pe, $health, $art, $electives);

    header ("Location: userpref.php");
}
}

这是 Controller ^^^

function setUserPref($studentPrefId, $studentId, $english, $math,               $science, $history, $oralcomm, $pe, $health, $art, $electives){
    DB::insertUpdate('student_pref', array(
    'student_pref_id'=>$studentPrefId
    ,'student_id'=>$studentId
    ,'english'=>$english
    ,'math'=>$math
    ,'science'=>$science
    ,'history'=>$history
    ,'oral_comm'=>$oralcomm
    ,'pe'=>$pe
    ,'health'=>$health
    ,'art'=>$art
    ,'electives'=>$electives));
}
function getStudentPref($studentID){
    return DB::query("SELECT * FROM student_pref WHERE student_id = %d", $studentID);
}

function limitUserPref($studentPrefId, $studentId) {
   return DB::query("SELECT * FROM student_pref WHERE student_pref_id = %d and student-id= %d", $studentPrefId, $studentId);

}

函数^^^

我不知道出了什么问题，提前致谢

Answer 1

看来您所做的检查是错误的。isset() 将确定变量是否已设置且不为 NULL。

有关 php isset 的更多信息 http://php.net/manual/en/function.isset.php

您正在检查的将永远是真实的 if(isset($result)< 1){

尝试以下操作

if(isset($_POST['userPrefSave'])){
    $studetnPrefId=$_POST['studentPrefId'];
    $studentId=$_POST['studentId'];

    $result= limitUserPref($studentPrefId,$studentId);
    //print_r($result);
    if(count($result) < 1){
    $studentPrefId=$_POST['studentPrefId'];
    $studentId=$_POST['studentId'];
    $english=$_POST['english'];
    $math=$_POST['math'];
    $science=$_POST['science'];
    $history=$_POST['history'];
    $oralComm=$_POST['oralComm'];
    $pe=$_POST['pe'];
    $health=$_POST['health'];
    $art=$_POST['art'];
    $electives=$_POST['electives'];
    setUserPref($studentPrefId, $studentId, $english, $math, $science,     $history, $oralComm, $pe, $health, $art, $electives);

header ("Location: userpref.php");
}
}