REST - post to get data. How else can this be done?

According to my understandings, you should not post to get data. For example, I'm on a project and we are posting to get data.

For example, this following.

{ "zipCOde":"85022", "city":"PHOENIX" "country":"US" "products":[ { "sku":"abc-21", "qty":2 }, { "sku":"def-13", "qty":2 } ] }

Does it make sense to post? How could this be done without posting? There could be 1 or more products.