Prestashop Custom Module, how to update my sql value?

I wish to update my sql value for my custom module, but since this value is in a separated sql table, I stuck ...

The first value, MY_TOPBAR, is updated correctly since she is updated in the ps_configuration table, but my second value, MY_HTML_DATA, isn't updated correctly in my table ps_mymodule.

Here is my php code :

public function getContent()
    {
        // If we try to update the settings
        $output = '';

        if (Tools::isSubmit('submit'.$this->name))
        {   
            Configuration::updateValue('MY_TOPBAR', Tools::getValue('MY_TOPBAR', ''));
            Configuration::updateValue('MY_HTML_DATA', Tools::getValue('MY_HTML_DATA', ''));
            Tools::redirectAdmin($this->context->link->getAdminLink('AdminModules').'&configure='.$this->name.'&tab_module='.$this->tab.'&conf=4&module_name='.$this->name);
        }
        return $output.$this->displayForm();
    }

How I can update correctly my MY_HTML_DATA value ?

Thanks

#

I finally used the method provided by @yenshirak and here it's the final code who permit to update my custom table, without loose of any html data =>

public function getContent()
    {
        // If we try to update the settings
        $output = '';

        if (Tools::isSubmit('submit'.$this->name))
        {   
            Configuration::updateValue('MY_TOPBAR', Tools::getValue('MY_TOPBAR', ''));
        $MY_HTML_DATA = pSQL( Tools::getValue('MY_HTML_DATA', ''), true );
        $sql='UPDATE `'._DB_PREFIX_.'mymodule` SET `data` = "'.$MY_HTML_DATA.'" WHERE `option` ='MY_HTML_DATA';';
        if(Db::getInstance()->Execute($sql))
            Tools::redirectAdmin($this->context->link->getAdminLink('AdminModules').'&configure='.$this->name.'&tab_module='.$this->tab.'&conf=4&module_name='.$this->name);
        }
        return $output.$this->displayForm();
    }