是否能在mongodb中获得最后30条收集结果的记录，但不是从零开始？

Question

I try to make this with .sort({_id:1}).limit(30) but in result they are showing from 0 to 30, but not from 40 to 70 (for example), that's mean i see all messages to 30, and newer than 30 - not showing. How i can find out actually 30 messages from db.collection('messages') ?

Answer 1

You can set the first document to be included in the results by calling skip() on the cursor:

.sort({_id: 1}).skip(40).limit(30)

Would provide the 41 through 70 documents after sorting by _id .

If you want to get the last 30 while keeping them in ascending order, reverse your sort, and then reverse the results using Array#reverse :

coll.find().sort({_id: -1}).limit(30).toArray((err, docs) => {
    docs.reverse();    
});