Edit a record saves a new record with updated fields

Question

I'm writing a small Joomla component for my school but there is a little problem with it.

When I go to edit a record and then save it, instead of updating that record, it saves it as a new record with updated field.

I have checked the button in view for any mistakes, but can't see any issues.

Can any one please tell me some common mistakes that could cause this issue?

Controller

class StudentControllerStudent extends JControllerForm
{
    public function __construct($config = array()) {
        parent::__construct($config);
    }
}

Model

class StudentModelStudent extends JModelAdmin
{
    public function getTable($type = 'Student', $prefix = 'StudentTable', $config = array())
    {
        return JTable::getInstance($type, $prefix, $config);
    }

        public function getForm($data = array(), $loadData = true) {
            $form = $this->loadForm('com_student.student', 'student',array('control' => 'jform', 'load_data' => $loadData));

            if (empty($form))
            {
                return false;
            }
            return $form;
        }

        protected function loadFormData() {
            return $this->getItem();
        }

}

view.html.php

class StudentViewStudent extends JViewLegacy {

    protected $state;
    protected $item;
    protected $form;

    /**
     * Display the view
     */
    public function display($tpl = null) {
        $this->state = $this->get('State');
        $this->item = $this->get('Item');
        $this->form = $this->get('Form');

        // Check for errors.
        if (count($errors = $this->get('Errors'))) {
            throw new Exception(implode("\n", $errors));
        }

        $this->addToolbar();
        parent::display($tpl);
    }


    protected function addToolbar() {
            JFactory::getApplication()->input->set('hidemainmenu', true);
            JToolbarHelper::title('edit item');
            JToolbarHelper::save('student.save');
            if (empty($this->item->id))
            {
                JToolbarHelper::cancel('student.cancel');
            }
            else
            {
                JToolbarHelper::cancel('student.cancel', 'JTOOLBAR_CLOSE');
            }
    }

}

Answer 1

Please try following:

1) You must create JTable class and add following code in it:

function __construct(&$db)
{
     parent::__construct('#__yourtablename', 'id', $db);
     // Assumes "id" should be primary key of your table.
}

2) Check in DB and make sure that you have primary key set for "#__yourtablename". Also it must be set as AUTO_INCREMENT if not then try following queries in your MySQL:

ALTER TABLE `#__yourtablename` ADD PRIMARY KEY(`id`);
ALTER TABLE `#__yourtablename` CHANGE `id` `id` INT(11) UNSIGNED NOT NULL AUTO_INCREMENT;

Again above assumes that, you have id column in your table.

Note: Replace "#__" with your table prefix.

Answer 2

Try this function loadFormData() for your model:

protected function loadFormData()
{
    $data = JFactory::getApplication()->getUserState('com_student.edit.student.data', array());

    if (empty($data))
    {
        $data = $this->getItem();
    }

    return $data;
}

Answer 3

In the view of your component. components->com_mycom->view->tmpl->default.php (or edit.php, some.php) depending on your needs.

<form action="<?php echo JRoute::_( 'index.php?option=com_student&view=student&layout=ifnotdefault&id='.$this->item->id ); ?>" method="post" class="form-validate" id="adminForm" enctype="multipart/form-data">

    <?php echo $this->form->renderField('id'); ?> // !important
    <?php echo $this->form->renderField('somefield'); ?>

    <input type="hidden" name="task" value="student.save" /> // !important
        <input type="submit" value="Save" />
        <?php echo JHtml::_( 'form.token' ); ?>

</form>

Check 'form action', Check 'field id', Check 'task'