Finding unprotected database using Shodan

How do i find unprotected/open databases using Shodan search?Got my answer. Anybody having same doubt can have a look here: https://www.securitynewspaper.com/2018/11/27/find-webcams-databases-boats-in-the-sea-using-shodan/

https://hackernoon.com/leaklooker-find-open-databases-in-a-second-9da4249c8472

https://sijmen.ruwhof.net/weblog/937-how-i-accidentally-found-a-huge-data-leak-during-a-college-lecture