If you want to customize any specific column properties, and let other columns be displayed from table definition, you can pass 2nd argument of `set_columns($cols,true)` to `true`. e.g.

$col = array();
$col["name"] = "company";
$col["edittype"] = "textarea";
$cols[] = $col;

$g->set_columns($cols,true);

You can make dropdown values based on passed query. It could be from same table.e.g.

$col["edittype"] = "select"; // render as select
$str = $g->get_dropdown_values("select productid as k, productname as v from products");
$col["editoptions"] = array("value"=>$str);