Install attribute in entity main table

Sometimes it is useful to add some fields to the attribute main table (f.e.: IDs from external systems like a middleware or a PIM). In the following example you can see how to add ID-fields to the category entity. Therefore I created a setupscript as an instance of Mage_Catalog_Model_Resource_Setup. Setup-model declaration in config.xml: <?xml version=”1.0″?> […]