我的更新无效，但它向我显示了成功的消息

My function is not working, though it shows the successful message that the data has been updated. But the data is still the same in the database also.

public function update(){
    $mysql = new Mysql();

    $query = "UPDATE module SET 
    modulename = '$this->name',
    modulecode = '$this->code',
    semesterid = '$this->semester',
    departmentid = '$this->department',
    programid = '$this->program'
    where moduleid = '$this->id';";

    $mysql->execute($query);
    if($mysql->result){
        $mysql->successMessage("Successfully Updated Data");
    }
}

if(isset($_POST['update'])){
    $module = new Module($_POST);
    $module->update();
}

Try to use:

$query = "UPDATE module SET 
    modulename = '".$this->name."',
    modulecode = '".$this->code."',
    semesterid = '".$this->semester."',
    departmentid = '".$this->department."',
    programid = '".$this->program."'
    where moduleid = '".$this->id;

I think you are looking for the number of rows affected by the query rather than the result.

Try mysql_affected_rows() to find out if anything was actually updated by the query.