Product Qty Maximum Bulk Edit

I use Easy Populate to upload my products. I am not sure how to edit the Product Qty Maximum to be 1, since there is only one of each item.

I put the stock at 1 of course, but instead of a buy now button, it allows you to add as many as you want to your cart.

How can I bulk edit (with or without EP) this option so I don't have to change 500 products one at a time?

Thanks in advance for any help. Please let me know if I can explain something further.

I should add, I processed this patch:

UPDATE products SET products_quantity_order_max=1;

but the listing page still shows the box that you can input a number. It says under the box "Max 1". I simply want this to have a button that says "Add to Cart".