How can I convert a product attribute type from Text to Dropdown in Magento?
I already have attribute values assigned to many products, so don't want to lose these in the process.
Magento Won't allow you to change input type of an attribute, and if you somehow change it from database, values of attributes would still not work for you, as Text stores just a value whereas dropdown stores id of each option's value
Instead of working on changing attribute type you can do this:
You need to export the data from magento exporter. Like, sku, your_attribute
Delete existing attribute
Create new one with the same attribute code your_attribute
Import the data that you have just exported