Node.Js - 如果在 MongoDB 中找不到匹配的文档，则返回 1

Question

Following query is written in MongoDB, I want to modify it such that when there is no matching record it should return 1.

Code :

 db.collection("uses").find({users:uid}).toArray((err,response) => {
    if(err){
        throw err;
    }
    if(response){
        res.json(uid);
    }
    else{
        res.json("1");
    }    
})

Answer 1

.find() would return a cursor & since you're using .toArray() on a cursor then it would return an array of objects/documents if any matched or else an empty array, So in your below code adding response.length should work :

 db.collection("uses").find({users:uid}).toArray((err,response) => {
    if(err){
        throw err;
    }
    if(response && response.length){
        res.json(uid);
    }
    else{
        res.json("1");
    }    
})