Hi Axel

Thank you for reaching out to us. 

What you would like to achieve is already default behavior for manual tables. If you don't add any values to a cell it will display as an empty cell 

but in the database it will be displayed like this

The same will happen if you delete a cell

I hope this helps, please do let us know if there is anything else we can assist you with.

Hi Axel

It does work with VARCHAR but it is only editable from the back-end, it will not work when edited from the front-end. If you set the column not to be editable then the NULL value will be added when you enter a new row. 

If "Editing" is enabled in the editing tab above the table then it will add an empty row.

I hope this helps, do let me know if you need any further assistance.

Hi Axel

I spoke to our developers and they are planning to add this to one of our future updates but they are not able to give us an exact ETA.

You can use the hook below.

Please do let us know if there is anything else we can assist you with.

// This filter is applied to the form data before is save in database.
//
// $formData contains the keys and values that will be inserted or updated in the table
//
// $table_id is the table identifier from the MySQL table (wp_wpdatatables).
function updateValuesBeforeSave($formData,$tableID){
    //Helper method that load columns config data from DB
    // $columnsData is array of objects that contain data from column settings
    $columnsData = \WDTConfigController::loadColumnsFromDB($tableID);
    foreach ($columnsData as $column){
        // check if column type is string
        if ($column->column_type == 'string') {
            //check if data from that string column is empty string
            if($formData[$column->orig_header] == '') {
                // set NULL value for string column that have empty data
                $formData[$column->orig_header] = NULL;
            }
        }
    }
    return $formData;
}
add_filter('wpdatatables_filter_formdata_before_save','updateValuesBeforeSave', 10, 2);
    

You are most welcome

Yes, for all tables that have a string column that is empty, when you submit the data through the editing module, they must be forwarded to the function as parameters, so you don't have to use them in the function itself.

I hope this helps, please don't hesitate to contact us if there is anything else we can assist you with.