I have a Magento 2.1 website and have setup a product attribute to be a drop down. However now I want to change the drop down to be a multi-select. I am wondering how I can do this via mysql. I have seen a few posts on how to do this in Magento 1.x however I am having an issue finding the needed mysql to run to change my product attribute from drop down to multi-select.
The product attribute I want to change has an id of 93