Convert Magento drop-down attribute into varchar attribute

magento-convert-drop-down-attribute-to-varchar.sql

INSERT INTO catalog_product_entity_varchar
	(entity_type_id, attribute_id, store_id, entity_id, `value`)
	SELECT
		4 AS entity_type_id,
		216 AS attribute_id,
		`existing_value`.store_id,
		`existing_option_id`.entity_id,
		`existing_value`.`value`
		FROM `eav_attribute_option_value` AS `existing_value`
		INNER JOIN catalog_product_entity_int AS `existing_option_id`
			ON `existing_option_id`.`value` = `existing_value`.option_id
		WHERE `existing_value`.option_id IN (
			SELECT option_id
				FROM eav_attribute_option AS att_option
				WHERE att_option.attribute_id = 216
		)
	ON DUPLICATE KEY UPDATE catalog_product_entity_varchar.entity_id = catalog_product_entity_varchar.entity_id;

DELETE FROM catalog_product_entity_int
	WHERE attribute_id = 216;

UPDATE eav_attribute
	SET backend_type = 'varchar'
	WHERE attribute_id = 216;

UPDATE catalog_eav_attribute
	SET is_global = 0
	WHERE attribute_id = 216;