MySQL或PHP PDO错误

Question

Im getting a:

Warning: PDOStatement::execute() [pdostatement.execute]: SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'classnum' cannot be null in /home/content/49/11554349/html/gb/dev/post.php on line 66

This is the php it refers too:

public function CheckIfEmptyTutor($class,$classnum,$studentyear){

    if(empty($class) && empty($classname) && empty($studentyear)){
        echo "All fields are requiered to create the post.";
        return true;
    }
    else{
        return false;
    }           
}


public function TutorPost($class,$classnum,$studentyear){

    $stmt = $this->db->prepare("INSERT INTO tutors(class, classnum, studenyear) VALUES(?,?,?)");
    $stmt->bindParam(1,$class);
    $stmt->bindParam(2,$classnum);
    $stmt->bindParam(3,$studentyear);
    $stmt->execute();       
    if($stmt->rowCount() == 1){
        echo "Successfully posted!";
    }
    //For testing purposes.
    else{
        echo "Something went wrong.";   
    }
}

Those are the functions I made, 1 is to check if the form is completely filled out, the other to actually post the data on the database.

And this is how im calling it in the html.

if(isset($_POST["submit"])){
    $class = $_POST["class"];
    $classnum = $_POST["classnum"];
    $studentyear = $_POST["studentyear"];
    $newpost = new UserPost();
    if(!$newpost->CheckIfEmptyTutor($class,$classnum,$studentyear)){
       $newpost->BookBoardPost($class,$classnum,$studentyear);
    }
}    

Answer 1

Your function is accepting a parameter called $classname but you are binding $classnum. Since there is no $classnum it is probably passing null into the statement.

$stmt->bindParam(2,$classname);

Answer 2

I think the function call has a problem , print out the data you sent to the function to make sure it's not null . Post it here or an a fiddle if you can

Answer 3

you have error:

public function CheckIfEmptyTutor($class,$classnum,$studentyear){
    if(empty($class) && empty($classname) && empty($studentyear)){

here should be

public function CheckIfEmptyTutor($class,$classnum,$studentyear){
    if(empty($class) || empty($classnum) || empty($studentyear)){