‫Finally, let's learn
‫how to delete documents in MongoDB.
‫So just like before,
‫we have delete one to delete one single document,
‫and we have delete many, well,
‫to delete multiple documents at the same time.
‫Alright, and just like before,
‫delete one will only work
‫for the first document matching your query.
‫And delete many will of course
‫work for all the documents matching your query.
‫Okay.
‫Just to get an overview of what we have here
‫at this moment in time,
‫let's do a find of all the tours.
‫And what I'm gonna do now
‫is to delete all the tours
‫which have a rating less than 4.8.
‫So that's gonna be just the first one
‫but if we had multiple tours with that condition,
‫then all of them would be deleted.
‫So db.tours.deleteMany.
‫So the condition is rating...
‫Open a new object
‫so that we can use the less than operator and 4.8.
‫Close it and then close this one.
‫And run this and here we see that it's deleted one document.
‫Right away it's telling us here
‫how many documents were affected by this operation.
‫So if we do this find now,
‫well then the first one that we had is gone.
‫Alright, so that's no problem.
‫We are only really using this here to play around
‫and so we can delete as much as we want here.
‫No problem.
‫Now if you wanna delete
‫all of the documents in the collection,
‫you would do it like this.
‫So deleteMany.
‫And I'm not gonna execute this.
‫But you would do it like this.
‫So all you have to do is pass in the empty object
‫because the empty object is basically a condition
‫that all of the documents always match.
‫It would be like simply using an empty object here in find.
‫I'm not gonna do that
‫and you should be careful with it,
‫especially when doing it in a real app
‫because you cannot come back from this operation.
‫So unless you have some backup in place,
‫this will effectively delete all the documents
‫in your collection,
‫in this case the tours collection.
‫So I'm not performing that.
‫I just wanted to show you
‫that this is how we delete everything.
‫So this is the simplest operation
‫and we don't use it all that often.
‫But I just wanted to have a short video
‫just to demonstrate that it also exists.